Polymers functionalized with heterocyclic nitrile compounds

ABSTRACT

A method for preparing a functionalized polymer, the method comprising the steps of preparing a reactive polymer and reacting the reactive polymer with a heterocyclic nitrile compound.

This invention claims priority from U.S. Provisional Patent ApplicationSer. No. 61/017,845, filed on Dec. 31, 2007, U.S. Provisional PatentApplication Ser. No. 60/999,679 filed on Oct. 19, 2007, and U.S.Provisional Patent Application Ser. No. 60/998,674 filed on Oct. 12,2007, which are incorporated herein by reference.

FIELD OF THE INVENTION

One or more embodiments of the present invention relates tofunctionalized polymers and methods for their manufacture.

BACKGROUND OF THE INVENTION

In the art of manufacturing tires, it is desirable to employ rubbervulcanizates that demonstrate reduced hysteresis, i.e., less loss ofmechanical energy to heat. For example, rubber vulcanizates that showreduced hysteresis are advantageously employed in tire components, suchas sidewalls and treads, to yield tires having desirably low rollingresistance. The hysteresis of a rubber vulcanizate is often attributedto the free polymer chain ends within the crosslinked rubber network, aswell as the dissociation of filler agglomerates. Functionalized polymershave been employed to reduce hysteresis of rubber vulcanizates. Thefunctional group of the functionalized polymer may reduce the number offree polymer chain ends via interaction with filler particles. Also, thefunctional group may reduce filler agglomeration. Nevertheless, whethera particular functional group imparted to a polymer can reducehysteresis is often unpredictable.

Functionalized polymers may be prepared by post-polymerization treatmentof reactive polymers with certain functionalizing agents. However,whether a reactive polymer can be functionalized by treatment with aparticular functionalizing agent can be unpredictable. For example,functionalizing agents that work for one type of polymer do notnecessarily work for another type of polymer, and vice versa.

Lanthanide-based catalyst systems are known to be useful forpolymerizing conjugated diene monomers to form polydienes having a highcontent of cis-1,4 linkage. The resulting cis-1,4-polydienes may displaypseudo-living characteristics in that, upon completion of thepolymerization, some of the polymer chains possess reactive ends thatcan react with certain functionalizing agents to yield functionalizedcis-1,4-polydienes.

The cis-1,4-polydienes produced with lanthanide-based catalyst systemstypically have a linear backbone, which is believed to provide bettertensile properties, higher abrasion resistance, lower hysteresis, andbetter fatigue resistance as compared to the cis-1,4-polydienes preparedwith other catalyst systems such as titanium-, cobalt-, and nickel-basedcatalyst systems. Therefore, the cis-1,4-polydienes made withlanthanide-based catalysts are particularly suitable for use in tirecomponents such as sidewalls and treads. However, one disadvantage ofthe cis-1,4-polydienes prepared with lanthanide-based catalysts is thatthe polymers exhibit high cold flow due to their linear backbonestructure. The high cold flow causes problems during storage andtransport of the polymers and also hinders the use of automatic feedingequipment in rubber compound mixing facilities.

Anionic initiators are known to be useful for the polymerization ofconjugated diene monomers to form polydienes having a combination of1,2-, cis-1,4- and trans-1,4-linkages. Anionic initiators are alsouseful for the copolymerization of conjugated diene monomers withvinyl-substituted aromatic compounds. The polymers prepared with anionicinitiators may display living characteristics in that, upon completionof the polymerization, the polymer chains possess living ends that arecapable of reacting with additional monomers for further chain growth orreacting with certain functionalizing agents to give functionalizedpolymers. Without the introduction of any coupled or branchedstructures, the polymers prepared with anionic initiators may alsoexhibit the problem of high cold flow.

Because functionalized polymers are advantageous, especially in themanufacture of tires, there exists a need to develop new functionalizedpolymers that give reduced hysteresis and reduced cold flow.

SUMMARY OF THE INVENTION

One or more embodiments of the present invention are directed toward amethod for preparing a functionalized polymer, the method comprising thesteps of preparing a reactive polymer and reacting the reactive polymerwith a heterocyclic nitrile compound.

One or more embodiments of the present invention are directed toward amethod for preparing a functional polymer, the method comprising thesteps of introducing conjugated diene monomer, optionally monomercopolymerizable therewith, and a catalyst or initiator to form apolymerization mixture; and adding a heterocyclic nitrile compound tothe polymerization mixture.

One or more embodiments of the present invention are directed toward amethod for preparing a polymer, the method comprising preparing anactive polymerization mixture and adding a heterocyclic nitrile compoundto the active polymerization mixture.

One or more embodiments of the present invention are directed toward afunctionalized polymer prepared by the steps of polymerizing monomer toform a reactive polymer and reacting the reactive polymer with aheterocyclic nitrile compound.

One or more embodiments of the present invention are directed toward afunctionalized polymer defined by at least one of the formulae:

where π is a polymer chain, θ is a heterocyclic group, and R is adivalent organic group.

One or more embodiments of the present invention are directed toward amethod for preparing a polymer, the method comprising preparing anactive polymerization mixture, adding a heterocyclic nitrile compound tothe active polymerization mixture, and adding a co-functionalizing agentto the active polymerization mixture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical plot of cold-flow gauge (mm at 8 min) versusMooney viscosity (ML 1+4 at 100° C.) for functionalizedcis-1,4-polybutadiene prepared according to one or more embodiments ofthe present invention as compared to unfunctionalizedcis-1,4-polybutadiene.

FIG. 2 is a graphical plot of hysteresis loss (tan δ) versus Mooneyviscosity (ML 1+4 at 130° C.) for vulcanizates prepared fromfunctionalized cis-1,4-polybutadiene prepared according to one or moreembodiments of the present invention as compared to vulcanizatesprepared from unfunctionalized cis-1,4-polybutadiene.

FIG. 3 is a graphical plot of cold-flow gauge (mm at 8 min) versusMooney viscosity (ML 1+4 at 100° C.) for functionalizedpoly(styrene-co-butadiene) prepared according to one or more embodimentsof the present invention as compared to unfunctionalizedpoly(styrene-co-butadiene).

FIG. 4 is a graphical plot of hysteresis loss (tan δ) versus Mooneyviscosity (ML 1+4 at 100° C.) for vulcanizates prepared fromfunctionalized poly(styrene-co-butadiene) prepared according to one ormore embodiments of the present invention as compared to vulcanizatesprepared from unfunctionalized poly(styrene-co-butadiene).

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

According to one or more embodiments of the present invention, areactive polymer is prepared by polymerizing conjugated diene monomerand optionally monomer copolymerizable therewith, and this reactivepolymer can then be functionalized by reaction with a heterocyclicnitrile compound. The resultant functionalized polymers can be used inthe manufacture of tire components. In one or more embodiments, theresultant functionalized polymers, which include cis-1,4-polydienes andpoly(styrene-co-butadiene), exhibit advantageous cold-flow resistanceand provide tire components that exhibit advantageously low hysteresis.

Examples of conjugated diene monomer include 1,3-butadiene, isoprene,1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene,2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene,4-methyl-1,3-pentadiene, and 2,4-hexadiene. Mixtures of two or moreconjugated dienes may also be utilized in copolymerization.

Examples of monomer copolymerizable with conjugated diene monomerinclude vinyl-substituted aromatic compounds such as styrene,p-methylstyrene, alpha-methylstyrene, and vinylnaphthalene.

In one or more embodiments, the reactive polymer is prepared bycoordination polymerization, wherein monomer is polymerized by using acoordination catalyst system. The key mechanistic features ofcoordination polymerization have been discussed in books (e.g., Kuran,W., Principles of Coordination Polymerization; John Wiley & Sons: NewYork, 2001) and review articles (e.g., Mulhaupt, R., MacromolecularChemistry and Physics 2003, volume 204, pages 289-327). Coordinationcatalysts are believed to initiate the polymerization of monomer by amechanism involving the coordination or complexation of monomer to anactive metal center prior to the insertion of monomer into a growingpolymer chain. An advantageous feature of coordination catalysts istheir ability to provide stereochemical control of polymerizations andthereby produce stereoregular polymers. As is known in the art, thereare numerous methods for creating coordination catalysts, but allmethods eventually generate an active intermediate that is capable ofcoordinating with monomer and inserting monomer into a covalent bondbetween an active metal center and a growing polymer chain. Thecoordination polymerization of conjugated dienes is believed to proceedvia π-allyl complexes as intermediates. Coordination catalysts can beone-, two-, three- or multi-component systems. In one or moreembodiments, a coordination catalyst may be formed by combining a heavymetal compound (e.g., a transition metal compound or a lanthanidecompound), an alkylating agent (e.g., an organoaluminum compound), andoptionally other co-catalyst components (e.g., a Lewis acid or a Lewisbase).

Various procedures can be used to prepare coordination catalysts. In oneor more embodiments, a coordination catalyst may be formed in situ byseparately adding the catalyst components to the monomer to bepolymerized in either a stepwise or simultaneous manner. In otherembodiments, a coordination catalyst may be preformed. That is, thecatalyst components are pre-mixed outside the polymerization systemeither in the absence of any monomer or in the presence of a smallamount of monomer. The resulting preformed catalyst composition may beaged, if desired, and then added to the monomer that is to bepolymerized.

Useful coordination catalyst systems include lanthanide-based catalystsystems. These catalyst systems may advantageously producecis-1,4-polydienes that, prior to quenching, have reactive chain endsand may be referred to as pseudo-living polymers. While othercoordination catalyst systems may also be employed, lanthanide-basedcatalysts have been found to be particularly advantageous, andtherefore, without limiting the scope of the present invention, will bediscussed in greater detail.

The practice of one or more embodiments of the present invention is notlimited by the selection of any particular lanthanide-based catalyst. Inone or more embodiments, the catalyst composition may include alanthanide compound, an alkylating agent, and a halogen-containingcompound that includes one or more labile halogen atoms. Where thelanthanide compound and/or alkylating agent include one or more labilehalogen atoms, the catalyst need not include a separatehalogen-containing compound; e.g., the catalyst may simply include ahalogenated lanthanide compound and an alkylating agent. In certainembodiments, the alkylating agent may include both an aluminoxane and atleast one other organoaluminum compound. In yet other embodiments, acompound containing a non-coordinating anion, or a non-coordinatinganion precursor, i.e., a compound that can undergo a chemical reactionto form a non-coordinating anion, may be employed in lieu of ahalogen-containing compound. In one embodiment, where the alkylatingagent includes an organoaluminum hydride compound, thehalogen-containing compound may be a tin halide as disclosed in U.S.Pat. No. 7,008,899, which is incorporated herein by reference. In theseor other embodiments, other organometallic compounds, Lewis bases,and/or catalyst modifiers may be employed in addition to the ingredientsor components set forth above. For example, in one embodiment, anickel-containing compound may be employed as a molecular weightregulator as disclosed in U.S. Pat. No. 6,699,813, which is incorporatedherein by reference.

Various lanthanide compounds or mixtures thereof can be employed. In oneor more embodiments, these compounds may be soluble in hydrocarbonsolvents such as aromatic hydrocarbons, aliphatic hydrocarbons, orcycloaliphatic hydrocarbons. In other embodiments, hydrocarbon-insolublelanthanide compounds, which can be suspended in the polymerizationmedium to form the catalytically active species, are also useful.

Lanthanide compounds may include at least one atom of lanthanum,neodymium, cerium, praseodymium, promethium, samarium, europium,gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium,lutetium, and didymium. Didymium may include a commercial mixture ofrare-earth elements obtained from monazite sand.

The lanthanide atom in the lanthanide compounds can be in variousoxidation states including but not limited to the 0, +2, +3, and +4oxidation states. Lanthanide compounds include, but are not limited to,lanthanide carboxylates, lanthanide organophosphates, lanthanideorganophosphonates, lanthanide organophosphinates, lanthanidecarbamates, lanthanide dithiocarbamates, lanthanide xanthates,lanthanide β-diketonates, lanthanide alkoxides or aryloxides, lanthanidehalides, lanthanide pseudo-halides, lanthanide oxyhalides, andorganolanthanide compounds.

Without wishing to limit the practice of the present invention, furtherdiscussion will focus on neodymium compounds, although those skilled inthe art will be able to select similar compounds that are based uponother lanthanide metals.

Neodymium carboxylates include neodymium formate, neodymium acetate,neodymium acrylate, neodymium methacrylate, neodymium valerate,neodymium gluconate, neodymium citrate, neodymium fumarate, neodymiumlactate, neodymium maleate, neodymium oxalate, neodymium2-ethylhexanoate, neodymium neodecanoate (a.k.a. neodymium versatate),neodymium naphthenate, neodymium stearate, neodymium oleate, neodymiumbenzoate, and neodymium picolinate.

Neodymium organophosphates include neodymium dibutyl phosphate,neodymium dipentyl phosphate, neodymium dihexyl phosphate, neodymiumdiheptyl phosphate, neodymium dioctyl phosphate, neodymiumbis(1-methylheptyl)phosphate, neodymium bis(2-ethylhexyl)phosphate,neodymium didecyl phosphate, neodymium didodecyl phosphate, neodymiumdioctadecyl phosphate, neodymium dioleyl phosphate, neodymium diphenylphosphate, neodymium bis(p-nonylphenyl)phosphate, neodymium butyl(2-ethylhexyl)phosphate, neodymium(1-methylheptyl)(2-ethylhexyl)phosphate, and neodymium(2-ethylhexyl)(p-nonylphenyl)phosphate.

Neodymium organophosphonates include neodymium butyl phosphonate,neodymium pentyl phosphonate, neodymium hexyl phosphonate, neodymiumheptyl phosphonate, neodymium octyl phosphonate,neodymium(1-methylheptyl)phosphonate,neodymium(2-ethylhexyl)phosphonate, neodymium decyl phosphonate,neodymium dodecyl phosphonate, neodymium octadecyl phosphonate,neodymium oleyl phosphonate, neodymium phenyl phosphonate,neodymium(p-nonylphenyl)phosphonate, neodymium butyl butylphosphonate,neodymium pentyl pentylphosphonate, neodymium hexyl hexylphosphonate,neodymium heptyl heptylphosphonate, neodymium octyl octylphosphonate,neodymium(1-methylheptyl)(1-methylheptyl)phosphonate,neodymium(2-ethylhexyl)(2-ethylhexyl)phosphonate, neodymium decyldecylphosphonate, neodymium dodecyl dodecylphosphonate, neodymiumoctadecyl octadecylphosphonate, neodymium oleyl oleylphosphonate,neodymium phenyl phenylphosphonate,neodymium(p-nonylphenyl)(p-nonylphenyl)phosphonate, neodymiumbutyl(2-ethylhexyl)phosphonate, neodymium(2-ethylhexyl)butylphosphonate,neodymium(1-methylheptyl)(2-ethylhexyl)phosphonate,neodymium(2-ethylhexyl) (1-methylheptyl)phosphonate,neodymium(2-ethylhexyl)(p-nonylphenyl)phosphonate, andneodymium(p-nonylphenyl)(2-ethylhexyl)phosphonate.

Neodymium organophosphinates include neodymium butylphosphinate,neodymium pentylphosphinate, neodymium hexylphosphinate, neodymiumheptylphosphinate, neodymium octylphosphinate,neodymium(1-methylheptyl)phosphinate,neodymium(2-ethylhexyl)phosphinate, neodymium decylphosphinate,neodymium dodecylphosphinate, neodymium octadecylphosphinate, neodymiumoleylphosphinate, neodymium phenylphosphinate,neodymium(p-nonylphenyl)phosphinate, neodymium dibutylphosphinate,neodymium dipentylphosphinate, neodymium dihexylphosphinate, neodymiumdiheptylphosphinate, neodymium dioctylphosphinate, neodymiumbis(1-methylheptyl)phosphinate, neodymium bis(2-ethylhexyl)phosphinate,neodymium didecylphosphinate, neodymium didodecylphosphinate, neodymiumdioctadecylphosphinate, neodymium dioleylphosphinate, neodymiumdiphenylphosphinate, neodymium bis(p-nonylphenyl)phosphinate, neodymiumbutyl(2-ethylhexyl)phosphinate,neodymium(1-methylheptyl)(2-ethylhexyl)phosphinate, andneodymium(2-ethylhexyl)(p-nonylphenyl)phosphinate.

Neodymium carbamates include neodymium dimethylcarbamate, neodymiumdiethylcarbamate, neodymium diisopropylcarbamate, neodymiumdibutylcarbamate, and neodymium dibenzylcarbamate.

Neodymium dithiocarbamates include neodymium dimethyldithiocarbamate,neodymium diethyldithiocarbamate, neodymium diisopropyldithiocarbamate,neodymium dibutyldithiocarbamate, and neodymium dibenzyldithiocarbamate.

Neodymium xanthates include neodymium methylxanthate, neodymiumethylxanthate, neodymium isopropylxanthate, neodymium butylxanthate, andneodymium benzylxanthate.

Neodymium β-diketonates include neodymium acetylacetonate, neodymiumtrifluoroacetylacetonate, neodymium hexafluoroacetylacetonate, neodymiumbenzoylacetonate, and neodymium 2,2,6,6-tetramethyl-3,5-heptanedionate.

Neodymium alkoxides or aryloxides include neodymium methoxide, neodymiumethoxide, neodymium isopropoxide, neodymium 2-ethylhexoxide, neodymiumphenoxide, neodymium nonylphenoxide, and neodymium naphthoxide.

Neodymium halides include neodymium fluoride, neodymium chloride,neodymium bromide, and neodymium iodide. Suitable neodymiumpseudo-halides include neodymium cyanide, neodymium cyanate, neodymiumthiocyanate, neodymium azide, and neodymium ferrocyanide. Suitableneodymium oxyhalides include neodymium oxyfluoride, neodymiumoxychloride, and neodymium oxybromide. Where neodymium halides,neodymium oxyhalides, or other neodymium compounds containing labilehalogen atoms are employed, the neodymium-containing compound can alsoserve as the halogen-containing compound. A Lewis base such astetrahydrofuran (THF) may be employed as an aid for solubilizing thisclass of neodymium compounds in inert organic solvents.

The term “organolanthanide compound” may refer to any lanthanidecompound containing at least one lanthanide-carbon bond. These compoundsare predominantly, though not exclusively, those containingcyclopentadienyl (Cp), substituted cyclopentadienyl, allyl, andsubstituted allyl ligands. Suitable organolanthanide compounds includeCp₃Ln, Cp₂LnR, Cp₂LnCl, CpLnCl₂, CpLn(cyclooctatetraene), (C₅Me₅)₂LnR,LnR₃, Ln(allyl)₃, and Ln(allyl)₂Cl, where Ln represents a lanthanideatom, and R represents a hydrocarbyl group.

Various alkylating agents, or mixtures thereof, can be used. Alkylatingagents, which may also be referred to as hydrocarbylating agents,include organometallic compounds that can transfer hydrocarbyl groups toanother metal. Typically, these agents include organometallic compoundsof electropositive metals such as Groups 1, 2, and 3 metals (Groups IA,IIA, and IIIA metals). In one or more embodiments, alkylating agentsinclude organoaluminum and organomagnesium compounds. Where thealkylating agent includes a labile halogen atom, the alkylating agentmay also serve as the halogen-containing compound.

The term “organoaluminum compound” may refer to any aluminum compoundcontaining at least one aluminum-carbon bond. In one or moreembodiments, organoaluminum compounds may be soluble in a hydrocarbonsolvent.

In one or more embodiments, organoaluminum compounds include thoserepresented by the formula AlR_(n)X_(3-n), where each R, which may bethe same or different, is a mono-valent organic group that is attachedto the aluminum atom via a carbon atom, where each X, which may be thesame or different, is a hydrogen atom, a halogen atom, a carboxylategroup, an alkoxide group, or an aryloxide group, and where n is aninteger of 1 to 3. In one or more embodiments, mono-valent organicgroups may include hydrocarbyl groups such as, but not limited to,alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, cycloalkenyl,substituted cycloalkenyl, aryl, substituted aryl, aralkyl, alkaryl,allyl, and alkynyl groups. These hydrocarbyl groups may containheteroatoms such as, but not limited to, nitrogen, oxygen, boron,silicon, sulfur, tin, and phosphorus atoms.

Types of organoaluminum compounds represented by the formulaAlR_(n)X_(3-n) include trihydrocarbylaluminum, dihydrocarbylaluminumhydride, hydrocarbylaluminum dihydride, dihydrocarbylaluminumcarboxylate, hydrocarbylaluminum bis(carboxylate), dihydrocarbylaluminumalkoxide, hydrocarbylaluminum dialkoxide, dihydrocarbylaluminum halide,hydrocarbylaluminum dihalide, dihydrocarbylaluminum aryloxide, andhydrocarbylaluminum diaryloxide compounds.

Trihydrocarbylaluminum compounds include trimethylaluminum,triethylaluminum, triisobutylaluminum, tri-n-propylaluminum,triisopropylaluminum, tri-n-butylaluminum, tri-t-butylaluminum,tri-n-pentylaluminum, trineopentylaluminum, tri-n-hexylaluminum,tri-n-octylaluminum, tris(2-ethylhexyl)aluminum, tricyclohexylaluminum,tris(1-methylcyclopentyl)aluminum, triphenylaluminum,tri-p-tolylaluminum, tris(2,6-dimethylphenyl)aluminum,tribenzylaluminum, diethylphenylaluminum, diethyl-p-tolylaluminum,diethylbenzylaluminum, ethyldiphenylaluminum, ethyldi-p-tolylaluminum,and ethyldibenzylaluminum.

Dihydrocarbylaluminum hydride compounds include diethylaluminum hydride,di-n-propylaluminum hydride, diisopropylaluminum hydride,di-n-butylaluminum hydride, diisobutylaluminum hydride,di-n-octylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminumhydride, dibenzylaluminum hydride, phenylethylaluminum hydride,phenyl-n-propylaluminum hydride, phenylisopropylaluminum hydride,phenyl-n-butylaluminum hydride, phenylisobutylaluminum hydride,phenyl-n-octylaluminum hydride, p-tolylethylaluminum hydride,p-tolyl-n-propylaluminum hydride, p-tolylisopropylaluminum hydride,p-tolyl-n-butylaluminum hydride, p-tolylisobutylaluminum hydride,p-tolyl-n-octylaluminum hydride, benzylethylaluminum hydride,benzyl-n-propylaluminum hydride, benzylisopropylaluminum hydride,benzyl-n-butylaluminum hydride, benzylisobutylaluminum hydride, andbenzyl-n-octylaluminum hydride.

Hydrocarbylaluminum dihydride compounds include ethylaluminum dihydride,n-propylaluminum dihydride, isopropylaluminum dihydride, n-butylaluminumdihydride, isobutylaluminum dihydride, and n-octylaluminum dihydride.

Dihydrocarbylaluminum halide compounds include diethylaluminum chloride,di-n-propylaluminum chloride, diisopropylaluminum chloride,di-n-butylaluminum chloride, diisobutylaluminum chloride,di-n-octylaluminum chloride, diphenylaluminum chloride,di-p-tolylaluminum chloride, dibenzylaluminum chloride,phenylethylaluminum chloride, phenyl-n-propylaluminum chloride,phenylisopropylaluminum chloride, phenyl-n-butylaluminum chloride,phenylisobutylaluminum chloride, phenyl-n-octylaluminum chloride,p-tolylethylaluminum chloride, p-tolyl-n-propylaluminum chloride,p-tolyisopropylaluminum chloride, p-tolyl-n-butylaluminum chloride,p-tolylisobutylaluminum chloride, p-tolyl-n-octylaluminum chloride,benzylethylaluminum chloride, benzyl-n-propylaluminum chloride,benzylisopropylaluminum chloride, benzyl-n-butylaluminum chloride,benzylisobutylaluminum chloride, and benzyl-n-octylaluminum chloride.

Hydrocarbylaluminum dihalide compounds include ethylaluminum dichloride,n-propylaluminum dichloride, isopropylaluminum dichloride,n-butylaluminum dichloride, isobutylaluminum dichloride, andn-octylaluminum dichloride.

Other organoaluminum compounds represented by the formula AlR_(n)X_(3-n)include dimethylaluminum hexanoate, diethylaluminum octoate,diisobutylaluminum 2-ethylhexanoate, dimethylaluminum neodecanoate,diethylaluminum stearate, diisobutylaluminum oleate, methylaluminumbis(hexanoate), ethylaluminum bis(octoate), isobutylaluminumbis(2-ethylhexanoate), methylaluminum bis(neodecanoate), ethylaluminumbis(stearate), isobutylaluminum bis(oleate), dimethylaluminum methoxide,diethylaluminum methoxide, diisobutylaluminum methoxide,dimethylaluminum ethoxide, diethylaluminum ethoxide, diisobutylaluminumethoxide, dimethylaluminum phenoxide, diethylaluminum phenoxide,diisobutylaluminum phenoxide, methylaluminum dimethoxide, ethylaluminumdimethoxide, isobutylaluminum dimethoxide, methylaluminum diethoxide,ethylaluminum diethoxide, isobutylaluminum diethoxide, methylaluminumdiphenoxide, ethylaluminum diphenoxide, and isobutylaluminumdiphenoxide.

Another class of organoaluminum compounds include aluminoxanes.Aluminoxanes include oligomeric linear aluminoxanes that can berepresented by the general formula:

and oligomeric cyclic aluminoxanes that can be represented by thegeneral formula:

where x may be an integer of 1 to about 100, and in other embodimentsabout 10 to about 50; y may be an integer of 2 to about 100, and inother embodiments about 3 to about 20; and where each R¹, which may bethe same or different, may be a mono-valent organic group that isattached to the aluminum atom via a carbon atom. Mono-valent organicgroups are defined above. It should be noted that the number of moles ofthe aluminoxane as used in this application refers to the number ofmoles of the aluminum atoms rather than the number of moles of theoligomeric aluminoxane molecules. This convention is commonly employedin the art of catalysis utilizing aluminoxanes.

Aluminoxanes can be prepared by reacting trihydrocarbylaluminumcompounds with water. This reaction can be performed according to knownmethods, such as (1) a method in which the trihydrocarbylaluminumcompound may be dissolved in an organic solvent and then contacted withwater, (2) a method in which the trihydrocarbylaluminum compound may bereacted with water of crystallization contained in, for example, metalsalts, or water adsorbed in inorganic or organic compounds, and (3) amethod in which the trihydrocarbylaluminum compound may be reacted withwater in the presence of the monomer or monomer solution that is to bepolymerized.

Aluminoxane compounds include methylaluminoxane (MAO), modifiedmethylaluminoxane (MMAO), ethylaluminoxane, n-propylaluminoxane,isopropylaluminoxane, butylaluminoxane, isobutylaluminoxane,n-pentylaluminoxane, neopentylaluminoxane, n-hexylaluminoxane,n-octylaluminoxane, 2-ethylhexylaluminoxane, cylcohexylaluminoxane,1-methylcyclopentylaluminoxane, phenylaluminoxane, and2,6-dimethylphenylaluminoxane. Modified methylaluminoxane can be formedby substituting about 20-80% of the methyl groups of methylaluminoxanewith C₂ to C₁₂ hydrocarbyl groups, preferably with isobutyl groups, byusing techniques known to those skilled in the art.

Aluminoxanes can be used alone or in combination with otherorganoaluminum compounds. In one embodiment, methylaluminoxane and atleast one other organoaluminum compound (e.g., AlR_(n)X_(3-n)) such asdiisobutyl aluminum hydride are employed in combination.

The term “organomagnesium compound” may refer to any magnesium compoundthat contains at least one magnesium-carbon bond. Organomagnesiumcompounds may be soluble in a hydrocarbon solvent. One class oforganomagnesium compounds that can be utilized may be represented by theformula MgR₂, where each R, which may be the same or different, is amono-valent organic group, with the proviso that the group is attachedto the magnesium atom via a carbon atom. In one or more embodiments,each R may be a hydrocarbyl group, and the resulting organomagnesiumcompounds are dihydrocarbylmagnesium compounds. Examples of thehydrocarbyl groups include, but are not limited to, alkyl, cycloalkyl,substituted cycloalkyl, alkenyl, cycloalkenyl, substituted cycloalkenyl,aryl, allyl, substituted aryl, aralkyl, alkaryl, and alkynyl groups.These hydrocarbyl groups may contain heteroatoms such as, but notlimited to, nitrogen, oxygen, silicon, sulfur, tin, and phosphorus atom.

Examples of suitable dihydrocarbylmagnesium compounds includediethylmagnesium, di-n-propylmagnesium, diisopropylmagnesium,dibutylmagnesium, dihexylmagnesium, diphenylmagnesium, anddibenzylmagnesium.

Another class of organomagnesium compounds that can be utilized includethose that may be represented by the formula RMgX, where R is amono-valent organic group, with the proviso that the group is attachedto the magnesium atom via a carbon atom, and X is a hydrogen atom, ahalogen atom, a carboxylate group, an alkoxide group, or an aryloxidegroup. Mono-valent groups are defined above. In one or more embodiments,X is a carboxylate group, an alkoxide group, or an aryloxide group.

Exemplary types of organomagnesium compounds represented by the formulaRMgX include hydrocarbylmagnesium hydride, hydrocarbylmagnesium halide,hydrocarbylmagnesium carboxylate, hydrocarbylmagnesium alkoxide, andhydrocarbylmagnesium aryloxide.

Specific examples of organomagnesium compounds represented by theformula RMgX include methylmagnesium hydride, ethylmagnesium hydride,butylmagnesium hydride, hexylmagnesium hydride, phenylmagnesium hydride,benzylmagnesium hydride, methylmagnesium chloride, ethylmagnesiumchloride, butylmagnesium chloride, hexylmagnesium chloride,phenylmagnesium chloride, benzylmagnesium chloride, methylmagnesiumbromide, ethylmagnesium bromide, butylmagnesium bromide, hexylmagnesiumbromide, phenylmagnesium bromide, benzylmagnesium bromide,methylmagnesium hexanoate, ethylmagnesium hexanoate, butylmagnesiumhexanoate, hexylmagnesium hexanoate, phenylmagnesium hexanoate,benzylmagnesium hexanoate, methylmagnesium ethoxide, ethylmagnesiumethoxide, butylmagnesium ethoxide, hexylmagnesium ethoxide,phenylmagnesium ethoxide, benzylmagnesium ethoxide, methylmagnesiumphenoxide, ethylmagnesium phenoxide, butylmagnesium phenoxide,hexylmagnesium phenoxide, phenylmagnesium phenoxide, and benzylmagnesiumphenoxide.

Various halogen-containing compounds, or mixtures thereof, that containone or more labile halogen atoms can be employed. Examples of halogenatoms include, but are not limited to, fluorine, chlorine, bromine, andiodine. A combination of two or more halogen-containing compounds havingdifferent halogen atoms can also be utilized. In one or moreembodiments, the halogen-containing compounds may be soluble in ahydrocarbon solvent. In other embodiments, hydrocarbon-insolublehalogen-containing compounds, which can be suspended in thepolymerization medium to form the catalytically active species, may beuseful.

Suitable types of halogen-containing compounds include elementalhalogens, mixed halogens, hydrogen halides, organic halides, inorganichalides, metallic halides, and organometallic halides.

Elemental halogens include fluorine, chlorine, bromine, and iodine.Mixed halogens include iodine monochloride, iodine monobromide, iodinetrichloride, and iodine pentafluoride.

Hydrogen halides include hydrogen fluoride, hydrogen chloride, hydrogenbromide, and hydrogen iodide.

Organic halides include t-butyl chloride, t-butyl bromides, allylchloride, allyl bromide, benzyl chloride, benzyl bromide,chloro-di-phenylmethane, bromo-di-phenylmethane, triphenylmethylchloride, triphenylmethyl bromide, benzylidene chloride, benzylidenebromide, methyltrichlorosilane, phenyltrichlorosilane,dimethyldichlorosilane, diphenyldichlorosilane, trimethylchlorosilane,benzoyl chloride, benzoyl bromide, propionyl chloride, propionylbromide, methyl chloroformate, and methyl bromoformate.

Inorganic halides include phosphorus trichloride, phosphorus tribromide,phosphorus pentachloride, phosphorus oxychloride, phosphorus oxybromide,boron trifluoride, boron trichloride, boron tribromide, silicontetrafluoride, silicon tetrachloride, silicon tetrabromide, silicontetraiodide, arsenic trichloride, arsenic tribromide, arsenic triiodide,selenium tetrachloride, selenium tetrabromide, tellurium tetrachloride,tellurium tetrabromide, and tellurium tetraiodide.

Metallic halides include tin tetrachloride, tin tetrabromide, aluminumtrichloride, aluminum tribromide, antimony trichloride, antimonypentachloride, antimony tribromide, aluminum triiodide, aluminumtrifluoride, gallium trichloride, gallium tribromide, gallium triiodide,gallium trifluoride, indium trichloride, indium tribromide, indiumtriiodide, indium trifluoride, titanium tetrachloride, titaniumtetrabromide, titanium tetraiodide, zinc dichloride, zinc dibromide,zinc diiodide, and zinc difluoride.

Organometallic halides include dimethylaluminum chloride,diethylaluminum chloride, dimethylaluminum bromide, diethylaluminumbromide, dimethylaluminum fluoride, diethylaluminum fluoride,methylaluminum dichloride, ethylaluminum dichloride, methylaluminumdibromide, ethylaluminum dibromide, methylaluminum difluoride,ethylaluminum difluoride, methylaluminum sesquichloride, ethylaluminumsesquichloride, isobutylaluminum sesquichloride, methylmagnesiumchloride, methylmagnesium bromide, methylmagnesium iodide,ethylmagnesium chloride, ethylmagnesium bromide, butylmagnesiumchloride, butylmagnesium bromide, phenylmagnesium chloride,phenylmagnesium bromide, benzylmagnesium chloride, trimethyltinchloride, trimethyltin bromide, triethyltin chloride, triethyltinbromide, di-t-butyltin dichloride, di-t-butyltin dibromide, dibutyltindichloride, dibutyltin dibromide, tributyltin chloride, and tributyltinbromide.

Compounds containing non-coordinating anions are known in the art. Ingeneral, non-coordinating anions are sterically bulky anions that do notform coordinate bonds with, for example, the active center of a catalystsystem due to steric hindrance. Exemplary non-coordinating anionsinclude tetraarylborate anions and fluorinated tetraarylborate anions.Compounds containing a non-coordinating anion also contain a countercation such as a carbonium, ammonium, or phosphonium cation. Exemplarycounter cations include triarylcarbonium cations andN,N-dialkylanilinium cations. Examples of compounds containing anon-coordinating anion and a counter cation include triphenylcarboniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, triphenylcarbonium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and N,N-dimethylaniliniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate.

Non-coordinating anion precursors include compounds that can form anon-coordinating anion under reaction conditions. Exemplarynon-coordinating anion precursors include triarylboron compounds, BR₃,where R is a strong electron-withdrawing aryl group such as apentafluorophenyl or 3,5-bis(trifluoromethyl)phenyl group.

The lanthanide-based catalyst composition used in this invention may beformed by combining or mixing the foregoing catalyst ingredients.Although one or more active catalyst species are believed to result fromthe combination of the lanthanide-based catalyst ingredients, the degreeof interaction or reaction between the various catalyst ingredients orcomponents is not known with any great degree of certainty. Therefore,the term “catalyst composition” has been employed to encompass a simplemixture of the ingredients, a complex of the various ingredients that iscaused by physical or chemical forces of attraction, a chemical reactionproduct of the ingredients, or a combination of the foregoing.

The foregoing lanthanide-based catalyst composition may have highcatalytic activity for polymerizing conjugated dienes intocis-1,4-polydienes over a wide range of catalyst concentrations andcatalyst ingredient ratios. Several factors may impact the optimumconcentration of any one of the catalyst ingredients. For example,because the catalyst ingredients may interact to form an active species,the optimum concentration for any one catalyst ingredient may bedependent upon the concentrations of the other catalyst ingredients.

In one or more embodiments, the molar ratio of the alkylating agent tothe lanthanide compound (alkylating agent/Ln) can be varied from about1:1 to about 1,000:1, in other embodiments from about 2:1 to about500:1, and in other embodiments from about 5:1 to about 200:1.

In those embodiments where both an aluminoxane and at least one otherorganoaluminum agent are employed as alkylating agents, the molar ratioof the aluminoxane to the lanthanide compound (aluminoxane/Ln) can bevaried from 5:1 to about 1,000:1, in other embodiments from about 10:1to about 700:1, and in other embodiments from about 20:1 to about 500:1;and the molar ratio of the at least one other organoaluminum compound tothe lanthanide compound (Al/Ln) can be varied from about 1:1 to about200:1, in other embodiments from about 2:1 to about 150:1, and in otherembodiments from about 5:1 to about 100:1.

The molar ratio of the halogen-containing compound to the lanthanidecompound is best described in terms of the ratio of the moles of halogenatoms in the halogen-containing compound to the moles of lanthanideatoms in the lanthanide compound (halogen/Ln). In one or moreembodiments, the halogen/Ln molar ratio can be varied from about 0.5:1to about 20:1, in other embodiments from about 1:1 to about 10:1, and inother embodiments from about 2:1 to about 6:1.

In yet another embodiment, the molar ratio of the non-coordinating anionor non-coordinating anion precursor to the lanthanide compound (An/Ln)may be from about 0.5:1 to about 20:1, in other embodiments from about0.75:1 to about 10:1, and in other embodiments from about 1:1 to about6:1.

The lanthanide-based catalyst composition can be formed by variousmethods.

In one embodiment, the lanthanide-based catalyst composition may beformed in situ by adding the catalyst ingredients to a solutioncontaining monomer and solvent, or to bulk monomer, in either a stepwiseor simultaneous manner. In one embodiment, the alkylating agent can beadded first, followed by the lanthanide compound, and then followed bythe halogen-containing compound, if used, or by the compound containinga non-coordinating anion or the non-coordinating anion precursor.

In another embodiment, the lanthanide-based catalyst composition may bepreformed. That is, the catalyst ingredients are pre-mixed outside thepolymerization system either in the absence of any monomer or in thepresence of a small amount of at least one conjugated diene monomer atan appropriate temperature, which may be from about −20° C. to about 80°C. The amount of conjugated diene monomer that may be used forpreforming the catalyst can range from about 1 to about 500 moles, inother embodiments from about 5 to about 250 moles, and in otherembodiments from about 10 to about 100 moles per mole of the lanthanidecompound. The resulting catalyst composition may be aged, if desired,prior to being added to the monomer that is to be polymerized.

In yet another embodiment, the lanthanide-based catalyst composition maybe formed by using a two-stage procedure. The first stage may involvecombining the alkylating agent with the lanthanide compound either inthe absence of any monomer or in the presence of a small amount of atleast one conjugated diene monomer at an appropriate temperature, whichmay be from about −20° C. to about 80° C. The amount of monomer employedin the first stage may be similar to that set forth above for performingthe catalyst. In the second stage, the mixture formed in the first stageand the halogen-containing compound, non-coordinating anion, ornon-coordinating anion precursor can be charged in either a stepwise orsimultaneous manner to the monomer that is to be polymerized.

In one or more embodiments, the reactive polymer is prepared by anionicpolymerization, wherein monomer is polymerized by using an anionicinitiator. The key mechanistic features of anionic polymerization havebeen described in books (e.g., Hsieh, H. L.; Quirk, R. P. AnionicPolymerization: Principles and Practical Applications; Marcel Dekker:New York, 1996) and review articles (e.g., Hadjichristidis, N.;Pitsikalis, M.; Pispas, S.; Iatrou, H.; Chem. Rev. 2001, 101(12),3747-3792). Anionic initiators may advantageously produce livingpolymers that, prior to quenching, are capable of reacting withadditional monomers for further chain growth or reacting with certainfunctionalizing agents to give functionalized polymers.

The practice of this invention is not limited by the selection of anyparticular anionic initiators. In one or more embodiments, the anionicinitiator employed is a functional initiator that imparts a functionalgroup at the head of the polymer chain (i.e., the location from whichthe polymer chain is started). In particular embodiments, the functionalgroup includes one or more heteroatoms (e.g., nitrogen, oxygen, boron,silicon, sulfur, tin, and phosphorus atoms) or heterocyclic groups. Incertain embodiments, the functional group reduces the 50° C. hysteresisloss of carbon-black filled vulcanizates prepared from polymerscontaining the functional group as compared to similar carbon-blackfilled vulcanizates prepared from polymer that does not include thefunctional group.

Exemplary anionic initiators include organolithium compounds. In one ormore embodiments, organolithium compounds may include heteroatoms. Inthese or other embodiments, organolithium compounds may include one ormore heterocyclic groups.

Types of organolithium compounds include alkyllithium, aryllithiumcompounds, and cycloalkyllithium compounds. Specific examples oforganolithium compounds include ethyllithium, n-propyllithium,isopropyllithium, n-butyllithium, sec-butyllithium, t-butyllithium,n-amyllithium, isoamyllithium, and phenyllithium. Other examples includealkylmagnesium halide compounds such as butylmagnesium bromide andphenylmagnesium bromide. Still other anionic initiators includeorganosodium compounds such as phenylsodium and2,4,6-trimethylphenylsodium. Also contemplated are those anionicinitiators that give rise to di-living polymers, wherein both ends of apolymer chain is living. Examples of such initiators include dilithioinitiators such as those prepared by reacting 1,3-diisopropenylbenzenewith sec-butyllithium. These and related difunctional initiators aredisclosed in U.S. Pat. No. 3,652,516, which is incorporated herein byreference. Radical anionic initiators may also be employed, includingthose described in U.S. Pat. No. 5,552,483, which is incorporated hereinby reference.

In particular embodiments, the organolithium compounds include a cyclicamine-containing compound such as lithiohexamethyleneimine. These andrelated useful initiators are disclosed in the U.S. Pat. Nos. 5,332,810,5,329,005, 5,578,542, 5,393,721, 5,698,646, 5,491,230, 5,521,309,5,496,940, 5,574,109, and 5,786,441, which are incorporated herein byreference. In other embodiments, the organolithium compounds includealkylthioacetals such as 2-lithio-2-methyl-1,3-dithiane. These andrelated useful initiators are disclosed in U.S. Publ. Nos. 2006/0030657,2006/0264590, and 2006/0264589, which are incorporated herein byreference. In still other embodiments, the organolithium compoundsinclude alkoxysilyl-containing initiators, such as lithiatedt-butyldimethylpropoxysilane. These and related useful initiators aredisclosed in U.S. Publ. No. 2006/0241241, which is incorporated hereinby reference.

In one or more embodiments, the anionic initiator employed istrialkyltinlithium compound such as tri-n-butyltinlithium. These andrelated useful initiators are disclosed in U.S. Pat. Nos. 3,426,006 and5,268,439, which are incorporated herein by reference.

When elastomeric copolymers containing conjugated diene monomers andvinyl-substituted aromatic monomers are prepared by anionicpolymerization, the conjugated diene monomers and vinyl-substitutedaromatic monomers may be used at a weight ratio of 95:5 to 50:50, or inother embodiments, 90:10 to 65:35. In order to promote the randomizationof comonomers in copolymerization and to control the microstructure(such as 1,2-linkage of conjugated diene monomer) of the polymer, arandomizer, which is typically a polar coordinator, may be employedalong with the anionic initiator.

Compounds useful as randomizers include those having an oxygen ornitrogen heteroatom and a non-bonded pair of electrons. Examples includelinear and cyclic oligomeric oxolanyl alkanes; dialkyl ethers of monoand oligo alkylene glycols (also known as glyme ethers); “crown” ethers;tertiary amines; linear THF oligomers; and the like. Linear and cyclicoligomeric oxolanyl alkanes are described in U.S. Pat. No. 4,429,091,which is incorporated herein by reference. Specific examples ofcompounds useful as randomizers include2,2-bis(2′-tetrahydrofuryl)propane, 1,2-dimethoxyethane,N,N,N′,N′-tetramethylethylenediamine (TMEDA), tetrahydrofuran (THF),1,2-dipiperidylethane, dipiperidylmethane, hexamethylphosphoramide,N—N′-dimethylpiperazine, diazabicyclooctane, dimethyl ether, diethylether, tri-n-butylamine, and mixtures thereof.

The amount of randomizer to be employed may depend on various factorssuch as the desired microstructure of the polymer, the ratio of monomerto comonomer, the polymerization temperature, as well as the nature ofthe specific randomizer employed. In one or more embodiments, the amountof randomizer employed may range between 0.05 and 100 moles per mole ofthe anionic initiator.

The anionic initiator and the randomizer can be introduced to thepolymerization system by various methods. In one or more embodiments,the anionic initiator and the randomizer may be added separately to themonomer to be polymerized in either a stepwise or simultaneous manner.In other embodiments, the anionic initiator and the randomizer may bepre-mixed outside the polymerization system either in the absence of anymonomer or in the presence of a small amount of monomer, and theresulting mixture may be aged, if desired, and then added to the monomerthat is to be polymerized.

Regardless of whether the reactive polymer is prepared by using acoordination catalyst or an anionic initiator, in one or moreembodiments, a solvent may be employed as a carrier to either dissolveor suspend the catalyst or initiator in order to facilitate the deliveryof the catalyst or initiator to the polymerization system. In otherembodiments, monomer can be used as the carrier. In yet otherembodiments, the catalyst or initiator can be used in their neat statewithout any solvent.

In one or more embodiments, suitable solvents include those organiccompounds that will not undergo polymerization or incorporation intopropagating polymer chains during the polymerization of monomer in thepresence of the catalyst or initiator. In one or more embodiments, theseorganic species are liquid at ambient temperature and pressure. In oneor more embodiments, these organic solvents are inert to the catalyst orinitiator. Exemplary organic solvents include hydrocarbons with a low orrelatively low boiling point such as aromatic hydrocarbons, aliphatichydrocarbons, and cycloaliphatic hydrocarbons. Non-limiting examples ofaromatic hydrocarbons include benzene, toluene, xylenes, ethylbenzene,diethylbenzene, and mesitylene. Non-limiting examples of aliphatichydrocarbons include n-pentane, n-hexane, n-heptane, n-octane, n-nonane,n-decane, isopentane, isohexanes, isopentanes, isooctanes,2,2-dimethylbutane, petroleum ether, kerosene, and petroleum spirits.And, non-limiting examples of cycloaliphatic hydrocarbons includecyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane.Mixtures of the above hydrocarbons may also be used. As is known in theart, aliphatic and cycloaliphatic hydrocarbons may be desirably employedfor environmental reasons. The low-boiling hydrocarbon solvents aretypically separated from the polymer upon completion of thepolymerization.

Other examples of organic solvents include high-boiling hydrocarbons ofhigh molecular weights, such as paraffinic oil, aromatic oil, or otherhydrocarbon oils that are commonly used to oil-extend polymers. Sincethese hydrocarbons are non-volatile, they typically do not requireseparation and remain incorporated in the polymer.

The production of the reactive polymer accoding to this invention can beaccomplished by polymerizing conjugated diene monomer, optionallytogether with monomer copolymerizable with conjugated diene monomer, inthe presence of a catalytically effective amount of a catalyst or aninitiator. The introduction of the catalyst or initiator, the conjugateddiene monomer, optionally the comonomer, and any solvent if employedforms a polymerization mixture in which the reactive polymer is formed.The amount of the catalyst or initiator to be employed may depend on theinterplay of various factors such as the type of catalyst or initiatoremployed, the purity of the ingredients, the polymerization temperature,the polymerization rate and conversion desired, the molecular weightdesired, and many other factors. Accordingly, a specific catalyst orinitiator amount cannot be definitively set forth except to say thatcatalytically effective amounts of the catalyst or initiator may beused.

In one or more embodiments, where a coordination catalyst (e.g., alanthanide-based catalyst) is employed, the amount of the coordinatingmetal compound (e.g., a lanthanide compound) used can be varied fromabout 0.001 to about 2 mmol, in other embodiments from about 0.005 toabout 1 mmol, and in still other embodiments from about 0.01 to about0.2 mmol per 100 gram of monomer.

In other embodiments, where an anionic initiator (e.g., an alkyllithiumcompound) is employed, the initiator loading may be varied from about0.05 to about 100 mmol, in other embodiments from about 0.1 to about 50mmol, and in still other embodiments from about 0.2 to about 5 mmol per100 gram of monomer.

In one or more embodiments, the polymerization may be carried out in apolymerization system that includes a substantial amount of solvent. Inone embodiment, a solution polymerization system may be employed inwhich both the monomer to be polymerized and the polymer formed aresoluble in the solvent. In another embodiment, a precipitationpolymerization system may be employed by choosing a solvent in which thepolymer formed is insoluble. In both cases, an amount of solvent inaddition to the amount of solvent that may be used in preparing thecatalyst or initiator is usually added to the polymerization system. Theadditional solvent may be the same as or different from the solvent usedin preparing the catalyst or initiator. Exemplary solvents have been setforth above. In one or more embodiments, the solvent content of thepolymerization mixture may be more than 20% by weight, in otherembodiments more than 50% by weight, and in still other embodiments morethan 80% by weight based on the total weight of the polymerizationmixture.

In other embodiments, the polymerization system employed may begenerally considered a bulk polymerization system that includessubstantially no solvent or a minimal amount of solvent. Those skilledin the art will appreciate the benefits of bulk polymerization processes(i.e., processes where monomer acts as the solvent), and therefore thepolymerization system includes less solvent than will deleteriouslyimpact the benefits sought by conducting bulk polymerization. In one ormore embodiments, the solvent content of the polymerization mixture maybe less than about 20% by weight, in other embodiments less than about10% by weight, and in still other embodiments less than about 5% byweight based on the total weight of the polymerization mixture. In stillanother embodiment, the polymerization mixture is substantially devoidof solvent, which refers to the absence of that amount of solvent thatwould otherwise have an appreciable impact on the polymerizationprocess. Polymerization systems that are substantially devoid of solventmay be referred to as including substantially no solvent. In particularembodiments, the polymerization mixture is devoid of solvent.

The polymerization may be conducted in any conventional polymerizationvessels known in the art. In one or more embodiments, solutionpolymerization can be conducted in a conventional stirred-tank reactor.In other embodiments, bulk polymerization can be conducted in aconventional stirred-tank reactor, especially if the monomer conversionis less than about 60%. In still other embodiments, especially where themonomer conversion in a bulk polymerization process is higher than about60%, which typically results in a highly viscous cement, the bulkpolymerization may be conducted in an elongated reactor in which theviscous cement under polymerization is driven to move by piston, orsubstantially by piston. For example, extruders in which the cement ispushed along by a self-cleaning single-screw or double-screw agitatorare suitable for this purpose. Examples of useful bulk polymerizationprocesses are disclosed in U.S. Publication No. 2005/0197474 A1, whichis incorporated herein by reference.

In one or more embodiments, all of the ingredients used for thepolymerization can be combined within a single vessel (e.g., aconventional stirred-tank reactor), and all steps of the polymerizationprocess can be conducted within this vessel. In other embodiments, twoor more of the ingredients can be pre-combined in one vessel and thentransferred to another vessel where the polymerization of monomer (or atleast a major portion thereof) may be conducted.

The polymerization can be carried out as a batch process, a continuousprocess, or a semi-continuous process. In the semi-continuous process,the monomer is intermittently charged as needed to replace that monomeralready polymerized. In one or more embodiments, the conditions underwhich the polymerization proceeds may be controlled to maintain thetemperature of the polymerization mixture within a range from about −10°C. to about 200° C., in other embodiments from about 0° C. to about 150°C., and in other embodiments from about 20° C. to about 100° C. In oneor more embodiments, the heat of polymerization may be removed byexternal cooling by a thermally controlled reactor jacket, internalcooling by evaporation and condensation of the monomer through the useof a reflux condenser connected to the reactor, or a combination of thetwo methods. Also, the polymerization conditions may be controlled toconduct the polymerization under a pressure of from about 0.1 atmosphereto about 50 atmospheres, in other embodiments from about 0.5 atmosphereto about 20 atmosphere, and in other embodiments from about 1 atmosphereto about 10 atmospheres. In one or more embodiments, the pressures atwhich the polymerization may be carried out include those that ensurethat the majority of the monomer is in the liquid phase. In these orother embodiments, the polymerization mixture may be maintained underanaerobic conditions.

Regardless of whether the polymerization is catalyzed or initiated by acoordination catalyst system (e.g., a lanthanide-based system) or ananionic initiator (e.g., an alkyllithium initiator), some or all of theresulting polymer chains may possess reactive ends, which are eitherpseudo-living or living, before the polymerization mixture is quenched.As noted above, the reactive polymer may be referred to as apseudo-living polymer where a coordination catalyst is employed or as aliving polymer where an anionic initiator is employed. In one or moreembodiments, a polymerzation mixture including reactive polymer may bereferred to as an active polymerization mixture. The percentage ofpolymer chains possessing a reactive end depends on various factors suchas the type of catalyst or initiator, the type of monomer, the purity ofthe ingredients, the polymerization temperature, the monomer conversion,and many other factors. In one or more embodiments, at least about 20%of the polymer chains possess a reactive end, in other embodiments atleast about 50% of the polymer chains possess a reactive end, and instill other embodiments at least about 80% of the polymer chains possessa reactive end. In any event, the reactive polymer can be reacted withheterocyclic nitrile compounds or mixtures thereof to form thefunctionalized polymer of this invention.

In one or more embodiments, heterocyclic nitrile compounds include atleast one —C≡N group (i.e. cyano or nitrile group) and at least oneheterocyclic group. In particlular embodiments, at least one cyano groupis directly attached to a heterocyclic group. In these or otherembodiments, at least one cyano group is indirectly attached to aheterocyclic group.

In one or more embodiments, heterocyclic nitrile compounds may berepresented by the formula θ-C≡N, where θ represents a heterocyclicgroup. In other embodiments, heterocyclic nitrile compounds may berepresented by the formula θ-R—C≡N, where θ represents a hetercyclicgroup and R represents a divalent organic group.

In one or more embodiments, divalent organic groups may includehydrocarbylene groups or substituted hydrocarbylene groups such as, butnot limited to, alkylene, cycloalkylene, substituted alkylene,substituted cycloalkylene, alkenylene, cycloalkenylene, substitutedalkenylene, substituted cycloalkenylene, arylene, and substitutedarylene groups. In one or more embodiments, each group may contain from1 carbon atom, or the appropriate minimum number of carbon atoms to formthe group, up to about 20 carbon atoms. Substituted hydrocarbylenegroups include a hydrocarbylene groups in which one or more hydrogenatoms have been replaced by a substituent such as an alkyl group. Thedivalent organic groups may also contain one or more heteroatoms suchas, but not limited to, nitrogen, oxygen, boron, silicon, sulfur, tin,and phosphorus atoms.

In one or more embodiments, θ may contain one or more additional cyanogroups (i.e., —C≡N), and as a result the heterocyclic nitrile compoundsmay therefore contain two or more cyano groups. In these or otherembodiments, the heterocyclic group may contain unsaturation and may bearomatic or non-aromatic. The heterocyclic group may contain oneheteroatom or multiple heteroatoms that are either the same or distinct.In particular embodiments, the heteroatoms may be selected from thegroup consisting of nitrogen, oxygen, sulfur, boron, silicon, tin, andphosphorus atoms. Also, the heterocyclic group may be monocyclic,bicyclic, tricyclic or multicyclic.

Representative examples of heterocyclic groups containing one or morenitrogen heteroatoms include 2-pyridyl, 3-pyridyl, 4-pyridyl, pyrazinyl,2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 3-pyridazinyl,4-pyridazinyl, N-methyl-2-pyrrolyl, N-methyl-3-pyrrolyl,N-methyl-2-imidazolyl, N-methyl-4-imidazolyl, N-methyl-5-imidazolyl,N-methyl-3-pyrazolyl, N-methyl-4-pyrazolyl, N-methyl-5-pyrazolyl,N-methyl-1,2,3-triazol-4-yl, N-methyl-1,2,3-triazol-5-yl,N-methyl-1,2,4-triazol-3-yl, N-methyl-1,2,4-triazol-5-yl,1,2,4-triazin-3-yl, 1,2,4-triazin-5-yl, 1,2,4-triazin-6-yl,1,3,5-triazinyl, N-methyl-2-pyrrolin-2-yl, N-methyl-2-pyrrolin-3-yl,N-methyl-2-pyrrolin-4-yl, N-methyl-2-pyrrolin-5-yl,N-methyl-3-pyrrolin-2-yl, N-methyl-3-pyrrolin-3-yl,N-methyl-2-imidazolin-2-yl, N-methyl-2-imidazolin-4-yl,N-methyl-2-imidazolin-5-yl, N-methyl-2-pyrazolin-3-yl,N-methyl-2-pyrazolin-4-yl, N-methyl-2-pyrazolin-5-yl, 2-quinolyl,3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl,N-methylindol-2-yl, N-methylindol-3-yl, N-methylisoindol-1-yl,N-methylisoindol-3-yl, 1-indolizinyl, 2-indolizinyl, 3-indolizinyl,1-phthalazinyl, 2-quinazolinyl, 4-quinazolinyl, 2-quinoxalinyl,3-cinnolinyl, 4-cinnolinyl, 1-methylindazol-3-yl, 1,5-naphthyridin-2-yl,1,5-naphthyridin-3-yl, 1,5-naphthyridin-4-yl, 1,8-naphthyridin-2-yl,1,8-naphthyridin-3-yl, 1,8-naphthyridin-4-yl, 2-pteridinyl,4-pteridinyl, 6-pteridinyl, 7-pteridinyl, 1-methylbenzimidazol-2-yl,6-phenanthridinyl, N-methyl-2-purinyl, N-methyl-6-purinyl,N-methyl-8-purinyl, N-methyl-β-carbolin-1-yl, N-methyl-β-carbolin-3-yl,N-methyl-β-carbolin-4-yl, 9-acridinyl, 1,7-phenanthrolin-2-yl,1,7-phenanthrolin-3-yl, 1,7-phenanthrolin-4-yl, 1,10-phenanthrolin-2-yl,1,10-phenanthrolin-3-yl, 1,10-phenanthrolin-4-yl,4,7-phenanthrolin-1-yl, 4,7-phenanthrolin-2-yl, 4,7-phenanthrolin-3-yl,1-phenazinyl, 2-phenazinyl, pyrrolidino, and piperidino groups.

Representative examples of heterocyclic groups containing one or moreoxygen heteroatoms include 2-furyl, 3-furyl, 2-benzo[b]furyl,3-benzo[b]furyl, 1-isobenzo[b]furyl, 3-isobenzo[b]furyl,2-naphtho[2,3-b]furyl, and 3-naphtho[2,3-b]furyl groups.

Representative examples of heterocyclic groups containing one or moresulfur heteroatoms include 2-thienyl, 3-thienyl, 2-benzo[b]thienyl,3-benzo[b]thienyl, 1-isobenzo[b]thienyl, 3-isobenzo[b]thienyl,2-naphtho[2,3-b]thienyl, and 3-naphtho[2,3-b]thienyl groups.

Representative examples of heterocyclic groups containing two or moredistinct heteroatoms include 2-oxazolyl, 4-oxazolyl, 5-oxazolyl,3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl,5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl,1,2,3-oxadiazol-4-yl, 1,2,3-oxadiazol-5-yl, 1,3,4-oxadiazol-2-yl,1,2,3-thiadiazol-4-yl, 1,2,3-thiadiazol-5-yl, 1,3,4-thiadiazol-2-yl,2-oxazolin-2-yl, 2-oxazolin-4-yl, 2-oxazolin-5-yl, 3-isoxazolinyl,4-isoxazolinyl, 5-isoxazolinyl, 2-thiazolin-2-yl, 2-thiazolin-4-yl,2-thiazolin-5-yl, 3-isothiazolinyl, 4-isothiazolinyl, 5-isothiazolinyl,2-benzothiazolyl, and morpholino groups.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-C≡N, where θ contains one or more nitrogen heteroatoms,include 2-pyridinecarbonitrile, 3-pyridinecarbonitrile,4-pyridinecarbonitrile, pyrazinecarbonitrile, 2-pyrimidinecarbonitrile,4-pyrimidinecarbonitrile, 5-pyrimidinecarbonitrile,3-pyridazinecarbonitrile, 4-pyridazinecarbonitrile,N-methyl-2-pyrrolecarbonitrile, N-methyl-3-pyrrolecarbonitrile,N-methyl-2-imidazolecarbonitrile, N-methyl-4-imidazolecarbonitrile,N-methyl-5-imidazolecarbonitrile, N-methyl-3-pyrazolecarbonitrile,N-methyl-4-pyrazolecarbonitrile, N-methyl-5-pyrazolecarbonitrile,N-methyl-1,2,3-triazole-4-carbonitrile,N-methyl-1,2,3-triazole-5-carbonitrile,N-methyl-1,2,4-triazole-3-carbonitrile,N-methyl-1,2,4-triazole-5-carbonitrile, 1,2,4-triazine-3-carbonitrile,1,2,4-triazine-5-carbonitrile, 1,2,4-triazine-6-carbonitrile,1,3,5-triazinecarbonitrile, N-methyl-2-pyrroline-2-carbonitrile,N-methyl-2-pyrroline-3-carbonitrile,N-methyl-2-pyrroline-4-carbonitrile,N-methyl-2-pyrroline-5-carbonitrile,N-methyl-3-pyrroline-2-carbonitrile,N-methyl-3-pyrroline-3-carbonitrile,N-methyl-2-imidazoline-2-carbonitrile,N-methyl-2-imidazoline-4-carbonitrile,N-methyl-2-imidazoline-5-carbonitrile,N-methyl-2-pyrazoline-3-carbonitrile,N-methyl-2-pyrazoline-4-carbonitrile,N-methyl-2-pyrazoline-5-carbonitrile, 2-quinolinecarbonitrile,3-quinolinecarbonitrile, 4-quinolinecarbonitrile,1-isoquinolinecarbonitrile, 3-isoquinolinecarbonitrile,4-isoquinolinecarbonitrile, N-methylindole-2-carbonitrile,N-methylindole-3-carbonitrile, N-methylisoindole-1-carbonitrile,N-methylisoindole-3-carbonitrile, 1-indolizinecarbonitrile,2-indolizinecarbonitrile, 3-indolizinecarbonitrile,1-phthalazinecarbonitrile, 2-quinazolinecarbonitrile,4-quinazolinecarbonitrile, 2-quinoxalinecarbonitrile,3-cinnolinecarbonitrile, 4-cinnolinecarbonitrile,1-methylindazole-3-carbonitrile, 1,5-naphthyridine-2-carbonitrile,1,5-naphthyridine-3-carbonitrile, 1,5-naphthyridine-4-carbonitrile,1,8-naphthyridine-2-carbonitrile, 1,8-naphthyridine-3-carbonitrile,1,8-naphthyridine-4-carbonitrile, 2-pteridinecarbonitrile,4-pteridinecarbonitrile, 6-pteridinecarbonitrile,7-pteridinecarbonitrile, 1-methylbenzimidazole-2-carbonitrile,phenanthridine-6-carbonitrile, N-methyl-2-purinecarbonitrile,N-methyl-6-purinecarbonitrile, N-methyl-8-purinecarbonitrile,N-methyl-β-carboline-1-carbonitrile,N-methyl-β-carboline-3-carbonitrile,N-methyl-β-carboline-4-carbonitrile, 9-acridinecarbonitrile,1,7-phenanthroline-2-carbonitrile, 1,7-phenanthroline-3-carbonitrile,1,7-phenanthroline-4-carbonitrile, 1,10-phenanthroline-2-carbonitrile,1,10-phenanthroline-3-carbonitrile, 1,10-phenanthroline-4-carbonitrile,4,7-phenanthroline-1-carbonitrile, 4,7-phenanthroline-2-carbonitrile,4,7-phenanthroline-3-carbonitrile, 1-phenazinecarbonitrile,2-phenazinecarbonitrile, 1-pyrrolidinecarbonitrile, and1-piperidinecarbonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-C≡N, where θ contains one or more oxygen heteroatoms, include2-furonitrile, 3-furonitrile 2-benzo[b]furancarbonitrile, 3-benzo[b]furancarbonitrile, isobenzo[b]furan-1-carbonitrile,isobenzo[b]furan-3-carbonitrile, naphtho[2,3-b]furan-2-carbonitrile, andnaphtho[2,3-b]furan-3-carbonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-C≡N, where θ contains one or more sulfur heteroatoms, include2-thiophenecarbonitrile, 3-thiophenecarbonitrile,benzo[b]thiophene-2-carbonitrile, benzo[b]thiophene-3-carbonitrile,isobenzo[b]thiophene-1-carbonitrile,isobenzo[b]thiophene-3-carbonitrile,naphtho[2,3-b]thiophene-2-carbonitrile, andnaphtho[2,3-b]thiophene-3-carbonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-C≡N, where θ contains two or more distinct heteroatoms,include 2-oxazolecarbonitrile, 4-oxazolecarbonitrile,5-oxazolecarbonitrile, 3-isoxazolecarbonitrile, 4-isoxazolecarbonitrile,5-isoxazolecarbonitrile, 2-thiazolecarbonitrile, 4-thiazolecarbonitrile,5-thiazolecarbonitrile, 3-isothiazolecarbonitrile,4-isothiazolecarbonitrile, 5-isothiazolecarbonitrile,1,2,3-oxadiazole-4-carbonitrile, 1,2,3-oxadiazole-5-carbonitrile,1,3,4-oxadiazole-2-carbonitrile, 1,2,3-thiadiazole-4-carbonitrile,1,2,3-thiadiazole-5-carbonitrile, 1,3,4-thiadiazole-2-carbonitrile,2-oxazoline-2-carbonitrile, 2-oxazoline-4-carbonitrile,2-oxazoline-5-carbonitrile, 3-isoxazolinecarbonitrile,4-isoxazolinecarbonitrile, 5-isoxazolinecarbonitrile,2-thiazoline-2-carbonitrile, 2-thiazoline-4-carbonitrile,2-thiazoline-5-carbonitrile, 3-isothiazolinecarbonitrile,4-isothiazolinecarbonitrile, 5-isothiazolinecarbonitrile,benzothiazole-2-carbonitrile, and 4-morpholinecarbonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-C≡N, where θ contains one or more cyano groups include2,3-pyridinedicarbonitrile, 2,4-pyridinedicarbonitrile,2,5-pyridinedicarbonitrile, 2,6-pyridinedicarbonitrile,3,4-pyridinedicarbonitrile, 2,4-pyrimidinedicarbonitrile,2,5-pyrimidinedicarbonitrile, 4,5-pyrimidinedicarbonitrile,4,6-pyrimidinedicarbonitrile, 2,3-pyrazinedicarbonitrile,2,5-pyrazinedicarbonitrile, 2,6-pyrazinedicarbonitrile,2,3-furandicarbonitrile, 2,4-furandicarbonitrile,2,5-furandicarbonitrile, 2,3-thiophenedicarbonitrile,2,4-thiophenedicarbonitrile, 2,5-thiophenedicarbonitrile,N-methyl-2,3-pyrroledicarbonitrile, N-methyl-2,4-pyrroledicarbonitrile,N-methyl-2,5-pyrroledicarbonitrile, 1,3,5-triazine-2,4-dicarbonitrile,1,2,4-triazine-3,5-dicarbonitrile, 1,2,4-triazine-3,6-dicarbonitrile,2,3,4-pyridinetricarbonitrile, 2,3,5-pyridinetricarbonitrile,2,3,6-pyridinetricarbonitrile, 2,4,5-pyridinetricarbonitrile,2,4,6-pyridinetricarbonitrile, 3,4,5-pyridinetricarbonitrile,2,4,5-pyrimidinetricarbonitrile, 2,4,6-pyrimidinetricarbonitrile,4,5,6-pyrimidinetricarbonitrile, pyrazinetricarbonitrile,2,3,4-furantricarbonitrile, 2,3,5-furantricarbonitrile,2,3,4-thiophenetricarbonitrile, 2,3,5-thiophenetricarbonitrile,N-methyl-2,3,4-pyrroletricarbonitrile,N-methyl-2,3,5-pyrroletricarbonitrile,1,3,5-triazine-2,4,6-tricarbonitrile, and1,2,4-triazine-3,5,6-tricarbonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-R—C≡N, where θ contains one or more nitrogen heteroatoms,include 2-pyridylacetonitrile, 3-pyridylacetonitrile,4-pyridylacetonitrile, pyrazinylacetonitrile, 2-pyrimidinylacetonitrile,4-pyrimidinylacetonitrile, 5-pyrimidinylacetonitrile,3-pyridazinylacetonitrile, 4-pyridazinylacetonitrile,N-methyl-2-pyrrolylacetonitrile, N-methyl-3-pyrrolylacetonitrile,N-methyl-2-imidazolylacetonitrile, N-methyl-4-imidazolylacetonitrile,N-methyl-5-imidazolylacetonitrile, N-methyl-3-pyrazolylacetonitrile,N-methyl-4-pyrazolylacetonitrile, N-methyl-5-pyrazolylacetonitrile,1,3,5-triazinylacetonitrile, 2-quinolylacetonitrile,3-quinolylacetonitrile, 4-quinolylacetonitrile,1-isoquinolylacetonitrile, 3-isoquinolylacetonitrile,4-isoquinolylacetonitrile, 1-indolizinylacetonitrile,2-indolizinylacetonitrile, 3-indolizinylacetonitrile,1-phthalazinylacetonitrile, 2-quinazolinylacetonitrile,4-quinazolinylacetonitrile, 2-quinoxalinylacetonitrile,3-cinnolinylacetonitrile, 4-cinnolinylacetonitrile,2-pteridinylacetonitrile, 4-pteridinylacetonitrile,6-pteridinylacetonitrile, 7-pteridinylacetonitrile,6-phenanthridinylacetonitrile, N-methyl-2-purinylacetonitrile,N-methyl-6-purinylacetonitrile, N-methyl-8-purinylacetonitrile,9-acridinylacetonitrile, 1,7-phenanthrolin-2-ylacetonitrile,1,7-phenanthrolin-3-ylacetonitrile, 1,7-phenanthrolin-4-ylacetonitrile,1,10-phenanthrolin-2-ylacetonitrile,1,10-phenanthrolin-3-ylacetonitrile,1,10-phenanthrolin-4-ylacetonitrile, 4,7-phenanthrolin-1-ylacetonitrile,4,7-phenanthrolin-2-ylacetonitrile, 4,7-phenanthrolin-3-ylacetonitrile,1-phenazinylacetonitrile, 2-phenazinylacetonitrile,pyrrolidinoacetonitrile, and piperidinoacetonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-R—C≡N, where θ contains one or more oxygen heteroatoms,include 2-furylacetonitrile, 3-furylacetonitrile,2-benzo[b]furylacetonitrile, 3-benzo[b]furylacetonitrile,1-isobenzo[b]furylacetonitrile, 3-isobenzo[b]furylacetonitrile,2-naphtho[2,3-b]furylacetonitrile, and3-naphtho[2,3-b]furylacetonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-R—C≡N, where θ contains one or more sulfur heteroatoms,include 2-thienylacetonitrile, 3-thienylacetonitrile,2-benzo[b]thienylacetonitrile, 3-benzo[b]thienylacetonitrile,1-isobenzo[b]thienylacetonitrile, 3-isobenzo[b]thienylacetonitrile,2-naphtho[2,3-b]thienylacetonitrile, and3-naphtho[2,3-b]thienylacetonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-R—C≡N, where θ contains two or more distinct heteroatoms,include 2-oxazolylacetonitrile, 4-oxazolylacetonitrile,5-oxazolylacetonitrile, 3-isoxazolylacetonitrile,4-isoxazolylacetonitrile, 5-isoxazolylacetonitrile,2-thiazolylacetonitrile, 4-thiazolylacetonitrile,5-thiazolylacetonitrile, 3-isothiazolylacetonitrile,4-isothiazolylacetonitrile, 5-isothiazolylacetonitrile,3-isoxazolinylacetonitrile, 4-isoxazolinylacetonitrile,5-isoxazolinylacetonitrile, 3-isothiazolinylacetonitrile,4-isothiazolinylacetonitrile, 5-isothiazolinylacetonitrile,2-benzothiazolylacetonitrile, and morpholinoacetonitrile.

Representative examples of heterocyclic nitrile compounds defined by theformula θ-R—C≡N, where θ contains one or more cyano groups, include2,3-pyridinediacetonitrile, 2,4-pyridinediacetonitrile,2,5-pyridinediacetonitrile, 2,6-pyridinediacetonitrile,3,4-pyridinediacetonitrile, 2,4-pyrimidinediacetonitrile,2,5-pyrimidinediacetonitrile, 4,5-pyrimidinediacetonitrile,4,6-pyrimidinediacetonitrile, 2,3-pyrazinediacetonitrile,2,5-pyrazinediacetonitrile, 2,6-pyrazinediacetonitrile,2,3-furandiacetonitrile, 2,4-furandiacetonitrile,2,5-furandiacetonitrile, 2,3-thiophenediacetonitrile,2,4-thiophenediacetonitrile, 2,5-thiophenediacetonitrile,N-methyl-2,3-pyrrolediacetonitrile, N-methyl-2,4-pyrrolediacetonitrile,N-methyl-2,5-pyrrolediacetonitrile, 1,3,5-triazine-2,4-diacetonitrile,1,2,4-triazine-3,5-diacetonitrile, 1,2,4-triazine-3,6-diacetonitrile,2,3,4-pyridinetriacetonitrile, 2,3,5-pyridinetriacetonitrile,2,3,6-pyridinetriacetonitrile, 2,4,5-pyridinetriacetonitrile,2,4,6-pyridinetriacetonitrile, 3,4,5-pyridinetriacetonitrile,2,4,5-pyrimidinetriacetonitrile, 2,4,6-pyrimidinetriacetonitrile,4,5,6-pyrimidinetriacetonitrile, pyrazinetriacetonitrile,2,3,4-furantriacetonitrile, 2,3,5-furantriacetonitrile,2,3,4-thiophenetriacetonitrile, 2,3,5-thiophenetriacetonitrile,N-methyl-2,3,4-pyrroletriacetonitrile,N-methyl-2,3,5-pyrroletriacetonitrile,1,3,5-triazine-2,4,6-triacetonitrile, and1,2,4-triazine-3,5,6-triacetonitrile.

The amount of the heterocyclic nitrile compound that can be added to thepolymerization mixture may depend on various factors including the typeand amount of catalyst or initiator used to initiate the polymerizationand the desired degree of functionalization. In one or more embodiments,where the reactive polymer is prepared by employing a lanthanide-basedcatalyst, the amount of the heterocyclic nitrile compound employed canbe described with reference to the lanthanide metal of the lanthanidecompound. For example, the molar ratio of the heterocyclic nitrilecompound to the lanthanide metal may be from about 1:1 to about 200:1,in other embodiments from about 5:1 to about 150:1, and in otherembodiments from about 10:1 to about 100:1.

In other embodiments, such as where the reactive polymer is prepared byusing an anionic initiator, the amount of the heterocyclic nitrilecompound employed can be described with reference to the amount of metalcation associated with the initiator. For example, where anorganolithium initiator is employed, the molar ratio of the heterocyclicnitrile compound to the lithium metal may be from about 0.3:1 to about2:1, in other embodiments from about 0.6:1 to about 1.5:1, and in otherembodiments from 0.8:1 to about 1.2:1.

In one or more embodiments, a co-functionalizing agent may also be addedto the polymerization mixture. A mixture of two or moreco-functionalizing agents may also be employed. The co-functionalizingagent may be added to the polymerization mixture prior to, togetherwith, or after the introduction of the heterocyclic nitrile compound. Inone or more embodiments, the co-functionalizing agent is added to thepolymerization mixture at least 5 minutes after, in other embodiments atleast 10 minutes after, and in other embodiments at least 30 minutesafter the introduction of the heterocyclic nitrile compound.

In one or more embodiments, co-functionalizing agents include compoundsor reagents that can react with a reactive polymer produced by thisinvention and thereby provide the polymer with a functional group thatis distinct from a propagating chain that has not been reacted with theco-functionalizing agent. The functional group may be reactive orinteractive with other polymer chains (propagating and/ornon-propagating) or with other constituents such as reinforcing fillers(e.g. carbon black) that may be combined with the polymer. In one ormore embodiments, the reaction between the co-functionalizing agent andthe reactive polymer proceeds via an addition or substitution reaction.

Useful co-functionalizing agents may include compounds that simplyprovide a functional group at the end of a polymer chain without joiningtwo or more polymer chains together, as well as compounds that cancouple or join two or more polymer chains together via a functionallinkage to form a single macromolecule. The latter type ofco-functionalizing agents may also be referred to as coupling agents.

In one or more embodiments, co-functionalizing agents include compoundsthat will add or impart a heteroatom to the polymer chain. In particularembodiments, co-functionalizing agents include those compounds that willimpart a functional group to the polymer chain to form a functionalizedpolymer that reduces the 50° C. hysteresis loss of a carbon-black filledvulcanizates prepared from the functionalized polymer as compared tosimilar carbon-black filled vulcanizates prepared fromnon-functionalized polymer. In one or more embodiments, this reductionin hysteresis loss is at least 5%, in other embodiments at least 10%,and in other embodiments at least 15%.

In one or more embodiments, suitable co-functionalizing agents includethose compounds that contain groups that may react with pseudo-livingpolymers (e.g., those produced in accordance with this invention).Exemplary co-functionalizing agents include ketones, quinones,aldehydes, amides, esters, isocyanates, isothiocyanates, epoxides,imines, aminoketones, aminothioketones, and acid anhydrides. Examples ofthese compounds are disclosed in U.S. Pat. Nos. 4,906,706, 4,990,573,5,064,910, 5,567,784, 5,844,050, 6,838,526, 6,977,281, and 6,992,147;U.S. Pat. Publication Nos. 2006/0004131 A1, 2006/0025539 A1,2006/0030677 A1, and 2004/0147694 A1; Japanese Patent Application Nos.05-051406A, 05-059103A, 10-306113A, and 11-035633A; which areincorporated herein by reference. Other examples of co-functionalizingagents include azine compounds as described in U.S. Ser. No. 11/640,711,hydrobenzamide compounds as disclosed in U.S. Ser. No. 11/710,713, nitrocompounds as disclosed in U.S. Ser. No. 11/710,845, and protected oximecompounds as disclosed in U.S. Ser. No. 60/875,484, all of which areincorporated herein by reference.

In particular embodiments, co-functionalizing agents include metalhalides, metalloid halides, alkoxysilanes, hydrocarbylmetalcarboxylates, hydrocarbylmetal ester-carboxylates, and alkoxystannanes.

In one or more embodiments, useful metal halides or metalloid halidesmay be selected from the group consisting of compounds represented bythe formulae (1) R¹ _(n)M¹X_(4-n), (2) M¹X₄, and (3) M²X₃, where each R¹in the formula (1) is individually a mono-valent organic groupcontaining 1 to about 20 carbon atoms, M¹ in the formulae (1) and (2)represents a tin atom, silicon atom, or germanium atom, M² in theformula (3) represents a phosphorous atom, X in the formulae (1)-(3)represents a halogen atom, and n in the formula (1) represents aninteger of from 0 to about 3.

Exemplary compounds represented by the formula (1) may includehalogenated organic metal compounds, and the compounds represented bythe formulae (2) and (3) may include halogenated metal compounds.

In the case where M¹ represents a tin atom, the compounds represented bythe formula (1) include triphenyltin chloride, tributyltin chloride,triisopropyltin chloride, trihexyltin chloride, trioctyltin chloride,diphenyltin dichloride, dibutyltin dichloride, dihexyltin dichloride,dioctyltin dichloride, phenyltin trichloride, butyltin trichloride, andoctyltin trichloride. Furthermore, the compounds represented by theformula (2) include tin tetrachloride, tin tetrabromide, and tintetraiodide.

In the case where M¹ represents a silicon atom, the compoundsrepresented by the formula (1) include triphenylchlorosilane,trihexylchlorosilane, trioctylchlorosilane, tributylchlorosilane,trimethylchlorosilane, diphenyldichlorosilane, dihexyldichlorosilane,dioctyldichlorosilane, dibutyldichlorosilane, dimethyldichlorosilane,methyltrichlorosilane, phenyltrichlorosilane, hexyltrichlorosilane,octyltrichlorosilane, butyltrichlorosilane, and methyltrichlorosilane.Furthermore, the compounds represented by the formula (2) includesilicon tetrachloride, silicon tetrabromide, and silicon tetraiodide

In the case where M¹ represents a germanium atom, the compoundsrepresented by the formula (1) include triphenylgermanium chloride,dibutylgermanium dichloride, diphenylgermanium dichloride, andbutylgermanium trichloride. Furthermore, the compounds represented bythe formula (2) include germanium tetrachloride, germanium tetrabromide,and germanium tetraiodide.

The compounds represented by the formula (3) include phosphoroustrichloride, phosphorous tribromide, and phosphorus triiodide.

In one or more embodiments, the alkoxysilanes may include at least onegroup selected from the group consisting of an epoxy group andisocyanate group.

Exemplary alkoxysilane compounds including an epoxy group include3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane,3-glycidyloxypropyltriphenoxysilane,(3-glycidyloxypropyl)methyldimethoxysilane,(3-glycidyloxypropyl)methyldiethoxysilane,(3-glycidyloxypropyl)methyldiphenoxysilane, condensation product of(3-glycidyloxypropyl)methyldimethoxysilane, condensation product of(3-glycidyloxypropyl)methyldiethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, condensation product of3-glycidyloxypropyltrimethoxysilane, and condensation product of3-glycidyloxypropyltrimethoxysilane.

Exemplary alkoxysilane compounds including an isocyanate group include3-isocyanatpropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane,3-isocyanatopropyltriphenoxysilane,(3-isocyanatopropyl)methyldimethoxysilane,(3-isocyanatopropyl)methyldiethoxysilane(3-isocyanatopropyl)methyldiphenoxysilane,condensation product of (3-isocyanatopropyl)methyldimethoxysilane,condensation product of (3-isocyanatopropyl)methylethoxysilane,β-(isocyanatocyclohexyl)ethyltrimethoxysilane, condensation product of(3-isocyanatopropyl)trimethoxysilane, and condensation product of(3-isocyanatopropyl)triethoxysilane.

In one or more embodiments, hydrocarbylmetal carboxylates may berepresented by the formula (4) R² _(m)M³(OC(O)R²)_(4-m), where each R²is individually a mono-valent organic group containing 1 to about 20carbon atoms, M³ represents a tin atom, silicon atom or germanium atom,and m represents an integer of 0-2.

Exemplary hydrocarbylmetal carboxylates include triphenyltin laurate,triphenyltin 2-ethylhexanoate, triphenyltin naphthenate, triphenyltinacetate, triphenyltin acrylate, tri-n-butyltin laurate, tri-n-butyltin2-ethylhexanoate, tri-n-butyltin naphthenate, tri-n-butyltin acetate,tri-n-butyltin acrylate, tri-t-butyltin laurate, tri-t-butyltin2-ethylhexanoate, tri-t-butyltin naphthenate, tri-t-butyltin acetate,tri-t-butyltin acrylate, triisobutyltin laurate, triisobutyltin2-ethylhexanoate, triisobutyltin naphthenate, triisobutyltin acetate,triisobutyltin acrylate, triisopropyltin laurate, triisopropyltin2-ethylhexanoate, triisopropyltin naphthenate, triisopropyltin acetate,triisopropyltin acrylate, trihexyltin laurate, trihexyltin2-ethylhexanoate, trihexyltin acetate, trihexyltin acrylate, trioctyltinlaurate, trioctyltin 2-ethylhexanoate, trioctyltin naphthenate,trioctyltin acetate, trioctyltin acrylate, tri-2-ethylhexyltin laurate,tri-2-ethylhexyltin 2-ethylhexanoate, tri-2-ethylhexyltin naphthenate,tri-2-ethylhexyltin acetate, tri-2-ethylhexyltin acrylate, tristearyltinlaurate, tristearyltin 2-ethylhexanoate, tristearyltin naphthenate,tristearyltin acetate, tristearyltin acrylate, tribenzyltin laurate,tribenzyltin 2-ethylhexanoate, tribenzyltin naphthenate, tribenzyltinacetate, tribenzyltin acrylate, diphenyltin dilaurate, diphenyltindi-2-ethylhexanoate, diphenyltin distearate, diphenyltin dinaphthenate,diphenyltin diacetate, diphenyltin diacrylate, di-n-butyltin dilaurate,di-n-butyltin di-2-ethylhexanoate, di-n-butyltin distearate,di-n-butyltin naphthenate, di-n-butyltin diacetate, di-n-butyltindiacrylate, di-t-butyltin dilaurate, di-t-butyltin di-2-ethylhexanoate,di-t-butyltin distearate, di-t-butyltin dinaphthenate, di-t-butyltindiacetate, di-t-butyltin diacrylate, diisobutyltin dilaurate,diisobutyltin di-2-ethylhexanoate, diisobutyltin distearate,diisobutyltin dinaphthenate, diisobutyltin diacetate, diisobutyltindiacrylate, diisopropyltin dilaurate, diisopropyltindi-2-ethylhexanoate, diisopropyltin distearate, diisopropyltindinaphthenate, diisopropyltin diacetate, diisopropyltin diacrylate,dihexyltin dilaurate, dihexyltin di-2-ethylhexanoate, dihexyltindistearate, dihexyltin dinaphthenate, dihexyltin diacetate, dihexyltindiacrylate, di-2-ethylhexyltin dilaurate, di-2-ethylhexyltindi-2-ethylhexanoate, di-2-ethylhexyltin distearate, di-2-ethylhexyltindinaphthenate, di-2-ethylhexyltin diacetate, di-2-ethylhexyltindiacrylate, dioctyltin dilaurate, dioctyltin di-2-ethylhexanoate,dioctyltin diacetate, dioctyltin diacrylate, distearyltin dilaurate,distearyltin di-2-ethylhexanoate, distearyltin distearate, distearyltindinaphthenate, distearyltin diacetate, distearyltin diacrylate,dibenzyltin dilaurate, dibenzyltin di-2-ethylhexanoate, dibenzyltindistearate, dibenzyltin dinaphthenate, dibenzyltin diacetate,dibenzyltin diacrylate, phenyltin trilaurate, phenyltintri-2-ethylhexanoate, phenyltin trinaphthenate, phenyltin triacetate,phenyltin triacrylate, n-butyltin trilaurate, n-butyltintri-2-ethylhexanoate, n-butyltin trinaphthenate, n-butyltin triacetate,n-butyltin triacrylate, tert-butyltin trilaurate, tert-butyltintri-2-ethylhexanoate, tert-butyltin trinaphthenate, tert-butyltintriacetate, tert-butyltin triacrylate, isobutyltin trilaurate,isobutyltin tri-2-ethylhexanoate, isobutyltin trinaphthenate,isobutyltin triacetate, isobutyltin triacrylate, isopropyltintrilaurate, isopropyltin tri-2-ethylhexanoate, isopropyltintrinaphthenate, isopropyltin triacetate, isopropyltin triacrylate,hexyltin trilaurate, hexyltin tri-2-ethylhexanoate, hexyltintrinaphthenate, hexyltin triacetate, hexyltin triacrylate, octyltintrilaurate octyltin tri-2-ethylhexanoate, octyltin trinaphthenate,octyltin triacetate, octyltin triacrylate, 2-ethylhexyltin trilaurate,2-ethylhexyltin tri-2-ethylhexanoate, 2-ethylhexyltin trinaphthenate,2-ethylhexyltin triacetate, 2-ethylhexyltin triacrylate, stearyltintrilaurate, stearyltin tri-2-ethylhexanoate, stearyltin trinaphthenate,stearyltin triacetate, stearyltin triacrylate, benzyltin trilaurate,benzyltin tri-2-ethylhexanoate, benzyltin trinaphthenate, benzyltintriacetate, and benzyltin triacrylate.

In one or more embodiments, hydrocarbylmetal ester-carboxylates may berepresented by the formula (5) R² _(m)M³(OCO—R³—CO(O)R²)_(4-m), whereeach R² is individually a mono-valent organic group containing 1 toabout 20 carbon atoms, R³ is a divalent organic group, M³ represents atin atom, silicon atom or germanium atom, and m represents an integer offrom 0 to 2.

Exemplary hydrocarbylmetal ester-carboxylates include diphenyltinbis(methylmaleate), diphenyltin bis(2-ethylhexylmaleate), diphenyltinbis(octyl maleate), diphenyltin bis(benzylmaleate), di-n-butyltinbis(methylmaleate), di-n-butyltin bis(2-ethylhexylmaleate),di-n-butyltin bis(octylmaleate), di-n-butyltin bis(benzylmaleate),di-t-butyltin bis(methylmaleate), di-t-butyltinbis(2-ethylhexylmaleate), di-t-butyltin bis(octylmaleate), di-t-butyltinbis(benzylmaleate), diisobutyltin bis(methylmaleate), diisobutyltinbis(2-ethylhexylmaleate), diisobutyltin bis(octylmaleate), diisobutyltinbis(benzylmaleate), diisopropyltin bis(methylmaleate), diisopropyltinbis(2-ethylhexylmaleate), diisopropyltin bis(octylmaleate),diisopropyltin bis(benzylmaleate), dihexyltin bis(methylmaleate),dihexyltin bis(2-ethylhexylmaleate), dihexyltin bis(octylmaleate),dihexyltin bis(benzylmaleate), di-2-ethylhexyltin bis(methylmaleate),di-2-ethylhexyltin bis(2-ethylhexylmaleate), di-2-ethylhexyltinbis(octylmaleate), di-2-ethylhexyltin bis(benzylmaleate), dioctyltinbis(methylmaleate), dioctyltin bis(2-ethylhexylmaleate), dioctyltinbis(octylmaleate), dioctyltin bis(benzylmaleate), distearyltinbis(methylmaleate), distearyltin bis(2-ethylhexylmaleate), distearyltinbis(octylmaleate), distearyltin bis(benzylmaleate), dibenzyltinbis(methylmaleate), dibenzyltin bis(2-ethylhexylmaleate), dibenzyltinbis(octylmaleate), dibenzyltin bis(benzylmaleate), diphenyltinbis(methyladipate), diphenyltin bis(2-ethylhexyladipate), diphenyltinbis(octyladipate), diphenyltin bis(benzyladipate), di-n-butyltinbis(methyladipate), di-n-butyltin bis(2-ethylhexyladipate),di-n-butyltin bis(octyladipate), di-n-butyltin bis(benzyladipate),di-t-butyltin bis(methyladipate), di-t-butyltinbis(2-ethylhexyladipate), di-t-butyltin bis(octyladipate), di-t-butyltinbis(benzyladipate), diisobutyltin bis(methyladipate), diisobutyltinbis(2-ethylhexyladipate), diisobutyltin bis(octyladipate), diisobutyltinbis(benzyladipate), diisopropyltin bis(methyladipate), diisopropyltinbis(2-ethylhexyladipate), diisopropyltin bis(octyladipate),diisopropyltin bis(benzyladipate), dihexyltin bis(methyladipate),dihexyltin bis(2-ethylhexyladipate), dihexyltin bis(methyladipate),dihexyltin bis(benzyladipate), di-2-ethylhexyltin bis(methyladipate),di-2-ethylhexyltin bis(2-ethylhexyladipate), di-2-ethylhexyltinbis(octyladipate), di-2-ethylhexyltin bis(benzyladipate), dioctyltinbis(methyladipate), dioctyltin bis(2-ethylhexyladipate), dioctyltinbis(octyladipate), dioctyltin bis(benzyladipate), distearyltinbis(methyladipate), distearyltin bis(2-ethylhexyladipate), distearyltinbis(octyladipate), distearyltin bis(benzyladipate), dibenzyltinbis(methyladipate), dibenzyltin bis(2-ethylhexyladipate), dibenzyltinbis(octyladipate), and dibenzyltin bis(benzyladipate).

The amount of the co-functionalizing agent that can be added to thepolymerization mixture may depend on various factors including the typeand amount of catalyst or initiator used to initiate the polymerizationand the desired degree of functionalization. In one or more embodiments,where the reactive polymer is prepared by employing a lanthanide-basedcatalyst, the amount of the co-functionalizing agent employed can bedescribed with reference to the lanthanide metal of the lanthanidecompound. For example, the molar ratio of the co-functionalizing agentto the lanthanide metal may be from about 1:1 to about 200:1, in otherembodiments from about 5:1 to about 150:1, and in other embodiments fromabout 10:1 to about 100:1. In one or more embodiments, the molar ratioof the co-functionalizing agent to the heterocyclic nitrile compound maybe from about 0.05:1 to about 1:1, in other embodiments from about 0.1:1to about 0.8:1, and in other embodiments from about 0.2:1 to about0.6:1.

In one or more embodiments, the heterocyclic nitrile compound (andoptionally the co-functionalizing agent) can be reacted with thereactive polymer after a desired monomer conversion is achieved butbefore the polymerization mixture is quenched by a quenching agent. Inone or more embodiments, the reaction between the heterocyclic nitrilecompound and the reactive polymer may take place within 30 minutes, inother embodiments within 5 minutes, and in other embodiments within oneminute after the peak polymerization temperature is reached. In one ormore embodiments, the reaction between the heterocyclic nitrile compoundand the reactive polymer can occur once the peak polymerizationtemperature is reached. In other embodiments, the reaction between theheterocyclic nitrile compound and the reactive polymer can occur afterthe reactive polymer has been stored. In one or more embodiments, thestorage of the reactive polymer occurs at room temperature or belowunder an inert atmosphere. In one or more embodiments, the reactionbetween the heterocyclic nitrile compound and the reactive polymer maytake place at a temperature from about 10° C. to about 150° C., and inother embodiments from about 20° C. to about 100° C. The time requiredfor completing the reaction between the heterocyclic nitrile compoundand the reactive polymer depends on various factors such as the type andamount of the catalyst or initiator used to prepare the reactivepolymer, the type and amount of the heterocyclic nitrile compound, aswell as the temperature at which the functionalization reaction isconducted. In one or more embodiments, the reaction between theheterocyclic nitrile compound and the reactive polymer can be conductedfor about 10 to 60 minutes.

In one or more embodiments, after the reaction between the reactivepolymer and the heterocyclic nitrile compound (and optionally theco-functionalizing agent) has been accomplished or completed, aquenching agent can be added to the polymerization mixture in order toinactivate any residual reactive polymer chains and the catalyst orcatalyst components. The quenching agent may include a protic compound,which includes, but is not limited to, an alcohol, a carboxylic acid, aninorganic acid, water, or a mixture thereof. An antioxidant such as2,6-di-tert-butyl-4-methylphenol may be added along with, before, orafter the addition of the quenching agent. The amount of the antioxidantemployed may be in the range of 0.2% to 1% by weight of the polymerproduct.

When the polymerization mixture has been quenched, the polymer productcan be recovered from the polymerization mixture by using anyconventional procedures of desolventization and drying that are known inthe art. For instance, the polymer can be recovered by subjecting thepolymer cement to steam desolventization, followed by drying theresulting polymer crumbs in a hot air tunnel. Alternatively, the polymermay be recovered by directly drying the polymer cement on a drum dryer.The content of the volatile substances in the dried polymer can be below1%, and in other embodiments below 0.5% by weight of the polymer.

While the reactive polymer and the heterocyclic nitrile compound (andoptionally the co-functionalizing agent) are believed to react toproduce novel functionalized polymers, the exact chemical structure ofthe functionalized polymer produced in every embodiment is not knownwith any great degree of certainty, particularly as the structurerelates to the residue imparted to the polymer chain end by theheterocyclic nitrile compound. Indeed, it is speculated that thestructure of the functionalized polymer may depend upon various factorssuch as the conditions employed to prepare the reactive polymer (e.g.,the type and amount of the catalyst or initiator) and the conditionsemployed to react the heterocyclic nitrile compound (and optionally theco-functionalizing agent) with the reactive polymer (e.g., the types andamounts of the heterocyclic nitrile compound and the co-functionalizingagent).

In one or more embodiments, one of the products resulting from thereaction between the heterocyclic nitrile compound and the reactivepolymer may be a functionalized polymer defined by one of the formulae:

where π is a polymer chain, and θ is a heterocyclic group as definedabove, and R is a divalent organic group as defined above.

It is believed that the functionalized polymers described by the aboveformulae may, upon exposure to moisture, convert to functionalizedpolymers that have a ketone-type structure and may be defined by one ofthe formulae:

where π is a polymer chain and θ is a heterocyclic group as definedabove, and R is a divalent organic group as defined above.

In one or more embodiments, the polymer chain (π) contains unsaturation.In these or other embodiments, the polymer chain is vulcanizable. In oneor more embodiments, the polymer chain (π) can have a glass transitiontemperature (T_(g)) that is less than 0° C., in other embodiments lessthan −20° C., and in other embodiments less than −30° C. In oneembodiment, the polymers may exhibit a single glass transitiontemperature.

In one or more embodiments, the polymer chain (e.g., π), preparedaccording to this invention may be cis-1,4-polydienes having acis-1,4-linkage content (which may be referred to as mer content) thatis greater than 60%, in other embodiments greater than about 75%, inother embodiments greater than about 90%, and in other embodimentsgreater than about 95%. Also, these polymers may have a 1,2-linkagecontent that is less than about 7%, in other embodiments less than 5%,in other embodiments less than 2%, and in other embodiments less than1%. The cis-1,4- and 1,2-linkage contents can be determined by infraredspectroscopy. The number average molecular weight (M_(n)) of thesepolymers may be from about 1,000 to about 1,000,000, in otherembodiments from about 5,000 to about 200,000, in other embodiments fromabout 25,000 to about 150,000, and in other embodiments from about50,000 to about 120,000, as determined by using gel permeationchromatography (GPC) calibrated with polystyrene standards andMark-Houwink constants for the polymer in question. The polydispersity(M_(w)/M_(n)) of these polymers may be from about 1.5 to about 5.0, andin other embodiments from about 2.0 to about 4.0.

In one or more embodiments, the polymer chain (e.g., π) preparedaccording to this invention may be medium or low cis polydienes (orpolydiene copolymers) including those prepared by anionic polymerizationtechniques. These polydienes can have a cis content of from about 10% to60%, in other embodiments from about 15% to 55%, and in otherembodiments from about 20% to about 50%, where the percentages are basedupon the number of diene mer units in the cis configuration versus thetotal number of diene mer units. These polydienes may also have a1,2-linkage content (i.e. vinyl content) from about 10% to about 90%, inother embodiments from about 10% to about 60%, in other embodiments fromabout 15% to about 50%, and in other embodiments from about 20% to about45%, where the percentages are based upon the number of diene mer unitsin the vinyl configuration versus the total number of diene mer units.The balance of the diene units may be in the trans-1,4-linkageconfiguration. In particular embodiments, where the polydiene polymersare prepared by employing a functional anionic initiator, the head ofthe polymer chain (e.g., π) includes a functional group that is theresidue of the functional initiator.

In particular embodiments, the polymer chain (e.g., π) are copolymers ofbutadiene, styrene, and optionally isoprene. These may include randomcopolymers. In other embodiments, the polymers are block copolymers ofpolybutadiene, polystyrene, and optionally polyisoprene. In particularembodiments, the polymers are hydrogenated or partially hydrogenated.

In one or more embodiments, the polymer chain (π) is ananionically-polymerized polymer selected from the group consisting ofpolybutadiene, functionalized polyisoprene, functionalizedpoly(styrene-co-butadiene), functionalizedpoly(styrene-co-butadiene-co-isoprene), functionalizedpoly(isoprene-co-styrene), and functionalizedpoly(butadiene-co-isoprene). The number average molecular weight (Mn) ofthese polymers may be from about 1,000 to about 1,000,000, in otherembodiments from about 5,000 to about 1,000,000, in other embodimentsfrom about 50,000 to about 500,000, and in other embodiments from about100,000 to about 300,000, as determined by using gel permeationchromatography (GPC) calibrated with polystyrene standards andMark-Houwink constants for the polymer in question. The polydispersity(M_(w)/M_(n)) of these polymers may be from about 1.0 to about 3.0, andin other embodiments from about 1.1 to about 2.0.

Advantageously, the functionalized polymers of this invention exhibitimproved cold-flow resistance and provide vulcanizates that demonstratereduced hysteresis. The functionalized polymers are particularly usefulin preparing tire components. These tire components can be prepared byusing the functionalized polymers alone or together with other rubberypolymers (i.e., polymers that can be vulcanized to form compositionspossessing elastomeric properties). Other rubbery polymers that may beused include natural and synthetic elastomers. The synthetic elastomerstypically derive from the polymerization of conjugated diene monomers.These conjugated diene monomers may be copolymerized with other monomerssuch as vinyl-substituted aromatic monomers. Other rubbery polymers mayderive from the polymerization of ethylene together with one or moreα-olefins and optionally one or more diene monomers.

Useful rubbery polymers include natural rubber, synthetic polyisoprene,polybutadiene, polyisobutylene-co-isoprene, neoprene,poly(ethylene-co-propylene), poly(styrene-co-butadiene),poly(styrene-co-isoprene), and poly(styrene-co-isoprene-co-butadiene),poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene),polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber,epichlorohydrin rubber, and mixtures thereof. These elastomers can havea myriad of macromolecular structures including linear, branched andstar shaped. Other ingredients that are typically employed in rubbercompounding may also be added.

The rubber compositions may include fillers such as inorganic andorganic fillers. The organic fillers include carbon black and starch.The inorganic fillers may include silica, aluminum hydroxide, magnesiumhydroxide, clays (hydrated aluminum silicates), and mixtures thereof.

A multitude of rubber curing agents (also called vulcanizing agents) maybe employed, including sulfur or peroxide-based curing systems. Curingagents are described in Kirk-Othmer, ENCYCLOPEDIA OF CHEMICALTECHNOLOGY, Vol. 20, pgs. 365-468, (3^(rd) Ed. 1982), particularlyVulcanization Agents and Auxiliary Materials, pgs. 390-402, and A. Y.Coran, Vulcanization, ENCYCLOPEDIA OF POLYMER SCIENCE AND ENGINEERING,(2^(nd) Ed. 1989), which are incorporated herein by reference.Vulcanizing agents may be used alone or in combination.

Other ingredients that may be employed include accelerators, oils,waxes, scorch inhibiting agents, processing aids, zinc oxide, tackifyingresins, reinforcing resins, fatty acids such as stearic acid, peptizers,and one or more additional rubbers.

These rubber compositions are useful for forming tire components such astreads, subtreads, black sidewalls, body ply skins, bead filler, and thelike. Preferably, the functional polymers are employed in tread andsidewall formulations. In one or more embodiments, these treadformulations may include from about 10% to about 100% by weight, inother embodiments from about 35% to about 90% by weight, and in otherembodiments from about 50% to 80% by weight of the functionalizedpolymer based on the total weight of the rubber within the formulation.

In one or more embodiments, the vulcanizable rubber composition may beprepared by forming an initial masterbatch that includes the rubbercomponent and filler (the rubber component optionally including thefunctionalized polymer of this invention). This initial masterbatch maybe mixed at a starting temperature of from about 25° C. to about 125° C.with a discharge temperature of about 135° C. to about 180° C. Toprevent premature vulcanization (also known as scorch), this initialmasterbatch may exclude vulcanizing agents. Once the initial masterbatchis processed, the vulcanizing agents may be introduced and blended intothe initial masterbatch at low temperatures in a final mixing stage,which preferably does not initiate the vulcanization process.Optionally, additional mixing stages, sometimes called remills, can beemployed between the masterbatch mixing stage and the final mixingstage. Various ingredients including the functionalized polymer of thisinvention can be added during these remills. Rubber compoundingtechniques and the additives employed therein are generally known asdisclosed in The Compounding and Vulcanization of Rubber, in RubberTechnology (2^(nd) Ed. 1973).

The mixing conditions and procedures applicable to silica-filled tireformulations are also well known as described in U.S. Pat. Nos.5,227,425, 5,719,207, 5,717,022, and European Patent No. 890,606, all ofwhich are incorporated herein by reference. In one or more embodiments,where silica is employed as a filler (alone or in combination with otherfillers), a coupling and/or shielding agent may be added to the rubberformulation during mixing. Useful coupling and shielding agents aredisclosed in U.S. Pat. Nos. 3,842,111, 3,873,489, 3,978,103, 3,997,581,4,002,594, 5,580,919, 5,583,245, 5,663,396, 5,674,932, 5,684,171,5,684,172, 5,696,197, 6,608,145, 6,667,362, 6,579,949, 6,590,017,6,525,118, 6,342,552, and 6,683,135, which are incorporated herein byreference. In one embodiment, the initial masterbatch is prepared byincluding the functionalized polymer of this invention and silica in thesubstantial absence of coupling and shielding agents.

Where the vulcanizable rubber compositions are employed in themanufacture of tires, these compositions can be processed into tirecomponents according to ordinary tire manufacturing techniques includingstandard rubber shaping, molding and curing techniques. Typically,vulcanization is effected by heating the vulcanizable composition in amold; e.g., it may be heated to about 140 to about 180° C. Cured orcrosslinked rubber compositions may be referred to as vulcanizates,which generally contain three-dimensional polymeric networks that arethermoset. The other ingredients, such as processing aides and fillers,may be evenly dispersed throughout the vulcanized network. Pneumatictires can be made as discussed in U.S. Pat. Nos. 5,866,171, 5,876,527,5,931,211, and 5,971,046, which are incorporated herein by reference.

In order to demonstrate the practice of the present invention, thefollowing examples have been prepared and tested. The examples shouldnot, however, be viewed as limiting the scope of the invention. Theclaims will serve to define the invention.

EXAMPLES Example 1 Synthesis of Unmodified cis-1,4-Polybutadiene

To a 2-gallon nitrogen-purged reactor equipped with turbine agitatorblades were added 1383 g of hexane and 3083 g of 20.6 wt % butadiene inhexane. A preformed catalyst was prepared by mixing 8.08 mL of 4.32 Mmethylaluminoxane (MAO) in toluene, 1.83 g of 20.6 wt % 1,3-butadiene inhexane, 0.65 mL of 0.537 M neodymium versatate (NdV) in cyclohexane,7.33 mL of 1.0 M diisobutylaluminum hydride (DIBAH) in hexane, and 1.40mL of 1.0 M diethylaluminum chloride (DEAC) in hexane. The catalyst wasaged for 15 minutes and charged into the reactor. The reactor jackettemperature was then set to 65° C. Forty five minutes after addition ofthe catalyst, the polymerization mixture was cooled to room temperature.The resulting polymer cement was coagulated with 12 liters ofisopropanol containing 5 g of 2,6-di-tert-butyl-4-methylphenol and thendrum-dried. The Mooney viscosity (ML₁₊₄) of the resulting polymer wasdetermined to be 26.5 at 100° C. by using a Monsanto Mooney viscometerwith a large rotor, a one-minute warm-up time, and a four-minute runningtime. As determined by gel permeation chromatography (GPC), the polymerhad a number average molecular weight (M_(n)) of 111,800, a weightaverage molecular weight (M_(w)) of 209,500, and a molecular weightdistribution (M_(w)/M_(n)) of 1.87. The infrared spectroscopic analysisof the polymer indicated a cis-1,4-linkage content of 94.4%, atrans-1,4-linkage content of 5.1%, and a 1,2-linkage content of 0.5%.The cold-flow resistance of the polymer was measured by using a Scottplasticity tester. Approximately 2.6 g of the polymer was molded, at100° C. for 20 minutes, into a cylindrical button with a diameter of 15mm and a height of 12 mm. After cooling down to room temperature, thebutton was removed from the mold and placed in a Scott plasticity testerat room temperature. A 5-kg load was applied to the specimen. After 8minutes, the residual gauge (i.e., sample thickness) was measured andtaken as an indication of the cold-flow resistance of the polymer.Generally, a higher residual gauge value indicates better cold-flowresistance. The properties of the unmodified cis-1,4-polybutadiene aresummarized in Table 1.

TABLE 1 Physical Properties of Unmodified and Modifiedcis-1,4-Polybutadiene Example No. Example 6 Example 7 Example 1 Example2 Example 3 Example 4 Example 5 (comparative) (compatative) Polymer typeunmodified unmodified 2-PyCN- PICN- PZCN- PhCN-modified CH₃CN-modifiedmodified modified modified ML₁₊₄ 26.5 44.2 44.0 57.9 50.6 29.1 33.4M_(n) 111,800 130,700 109,400 94,900 106,300 111,400 111,500 M_(w)209,500 260,500 213,200 182,600 199,100 200,900 209,300 M_(w)/M_(n) 1.871.99 1.95 1.92 1.87 1.80 1.81 Cold-flow gauge 1.72 2.28 2.88 3.55 3.611.95 2.08 (mm at 8 min.) % cis-1,4 94.5 95.0 94.8 94.3 94.3 94.4 94.5 %trans-1,4 5.0 4.5 4.7 5.2 5.2 5.0 4.9 % 1,2- 0.5 0.5 0.5 0.5 0.5 0.6 0.6

Example 2 Synthesis of Unmodified cis-1,4-Polybutadiene

To a 2-gallon nitrogen-purged reactor equipped with turbine agitatorblades were added 1631 g of hexane and 2835 g of 22.4 wt % butadiene inhexane. A preformed catalyst was prepared by mixing 6.10 mL of 4.32 MMAO in toluene, 1.27 g of 22.4 wt % 1,3-butadiene in hexane, 0.49 mL of0.537 M NdV in cyclohexane, 5.53 mL of 1.0 M DIBAH in hexane, and 1.05mL of 1.0 M DEAC in hexane. The catalyst was aged for 15 minutes andcharged into the reactor. The reactor jacket temperature was then set to65° C. Seventy two minutes after addition of the catalyst, thepolymerization mixture was cooled to room temperature. The resultingpolymer cement was coagulated with 12 liters of isopropanol containing 5g of 2,6-di-tert-butyl-4-methylphenol and then drum-dried. Theproperties of the resulting unmodified cis-1,4-polybutadiene aresummarized in Table 1.

Example 3 Synthesis of cis-1,4-Polybutadiene Modified with2-Pyridinecarbonitrile (2-PyCN)

To a 2-gallon nitrogen-purged reactor equipped with turbine agitatorblades were added 1670 g of hexane and 2810 g of 22.6 wt % butadiene inhexane. A preformed catalyst was prepared by mixing 7.35 mL of 4.32 MMAO in toluene, 1.52 g of 22.6 wt % 1,3-butadiene in hexane, 0.59 mL of0.537 M NdV in cyclohexane, 6.67 mL of 1.0 M DIBAH in hexane, and 1.27mL of 1.0 M DEAC in hexane. The catalyst was aged for 15 minutes andcharged into the reactor. The reactor jacket temperature was then set to65° C. Sixty minutes after addition of the catalyst, the polymerizationmixture was cooled to room temperature.

425 g of the resulting unmodified polymer cement (i.e., pseudo-livingpolymer cement) was transferred from the reactor to a nitrogen-purgedbottle, followed by addition of 5.93 mL of 0.442 M2-pyridinecarbonitrile (2-PyCN) in toluene. The bottle was tumbled for25 minutes in a water bath maintained at 65° C. The resulting mixturewas coagulated with 3 liters of isopropanol containing 0.5 g of2,6-di-tert-butyl-4-methylphenol and then drum-dried. The properties ofthe resulting 2-PyCN-modified polymer are summarized in Table 1.

Example 4 Synthesis of cis-1,4-Polybutadiene Modified with2-Pyrimidinecarbonitrile (PICN)

cis-1,4-polybutadiene modified with 2-pyrimidinecarbonitrile (PICN) wasprepared by reacting 422 g of the pseudo-living polymer cement fromExample 3 with 3.94 mL of 0.779 M PICN in toluene. The reactionconditions and polymer work-up procedure were identical to those inExample 3. The properties of the resulting PICN-modifiedcis-1,4-polybutadiene are summarized in Table 1.

Example 5 Synthesis of cis-1,4-Polybutadiene Modified withPyrazinecarbonitrile (PZCN)

cis-1,4-polybutadiene modified with pyrazinecarbonitrile (PZCN) wasprepared by reacting 426 g of the pseudo-living polymer cement fromExample 3 with 3.84 mL of 0.808 M PZCN in toluene. The reactionconditions and polymer work-up procedure were identical to those inExample 3. The properties of the resulting PZCN-modifiedcis-1,4-polybutadiene are summarized in Table 1.

Example 6 (Comparative Example) Synthesis of cis-1,4-PolybutadieneModified with Benzonitrile (PhCN)

cis-1,4-polybutadiene modified with benzonitrile (PhCN) was prepared byreacting 423 g of the pseudo-living polymer cement from Example 3 with4.03 mL of 0.676 M PhCN in toluene. The reaction conditions and polymerwork-up procedure were identical to those in Example 3. The propertiesof the resulting PhCN-modified cis-1,4-polybutadiene are summarized inTable 1.

Example 7 (Comparative Example) Synthesis of cis-1,4-PolybutadieneModified with Acetonitrile (CH₃CN)

cis-1,4-polybutadiene modified with acetonitrile (CH₃CN) was prepared byreacting 437 g of the pseudo-living polymer cement from Example 3 with5.00 mL of 0.539 M CH₃CN in toluene. The reaction conditions and polymerwork-up procedure were identical to those in Example 3. The propertiesof the resulting CH₃CN-modified cis-1,4-polybutadiene are summarized inTable 1.

In FIG. 1, the cold-flow resistance of the unmodified or modifiedcis-1,4-polybutadiene samples synthesized in Examples 1-7 is plottedagainst the polymer Mooney viscosity. The data indicate that, at thesame polymer Mooney viscosity, the 2-PyCN—, PICN—, and PZCN-modifiedpolymers show much higher residual cold-flow gauge values andaccordingly much better cold-flow resistance than the unmodifiedpolymer. On the other hand, both PhCN— and CH₃CN-modified polymersprovide no or very marginal improvement in cold-flow resistance ascompared to unmodified polymer.

Examples 8-14 Compounding Evaluation of 2-PyCN—, PICN—, PZCN—, PhCN—,and CH₃CN-modified cis-1,4-Polybutadiene versus Unmodifiedcis-1,4-Polybutadiene

The cis-1,4-Polybutadiene samples produced in Examples 1-7 wereevaluated in a carbon black filled rubber compound. The compositions ofthe vulcanizates are presented in Table 2, wherein the numbers areexpressed as parts by weight per hundred parts by weight of rubber (phr)

TABLE 2 COMPOSITIONS OF RUBBER VULCANIZATES MADE FROMCIS-1,4-POLYBUTADIENE Ingredients Amount (phr) Cis-1,4-Polybutadiene 80Polyisoprene 20 Carbon black 50 Oil 10 Wax 2 Antioxidant 1 Stearic acid2 Zinc oxide 2.5 Accelerators 1.3 Sulfur 1.5 Total 170.3

The Mooney viscosity (ML₁₊₄) of the uncured compound was determined at130° C. by using a Alpha Technologies Mooney viscometer with a largerotor, a one-minute warm-up time, and a four-minute running time. Thetensile at break (T_(b)), and the elongation at break (E_(b)) weredetermined according to ASTM D412. The Payne effect data (ΔG′) andhysteresis data (tan δ) of the vulcanizates were obtained from a dynamicstrain sweep experiment, which was conducted at 50° C. and 15 Hz withstrain sweeping from 0.1% to 20%. ΔG′ is the difference between G′ at0.1% strain and G′ at 20% strain. The physical properties of thevulcanizates are summarized in Table 3 and FIG. 2.

TABLE 3 Physical Properties of Rubber Vulcanizates Prepared fromcis-1,4-Polybutadiene Example No. Example 8 Example 9 Example 10 Example11 Example 12 Example 13 Example 14 Polymer used Example 1 Example 2Example 3 Example 4 Example 5 Example 6 Example 7 Polymer typeunmodified unmodified 2-PyCN- PICN- PZCN- PhCN- CH₃CN- modified modifiedmodified modified modified ML₁₊₄ 50.3 68.3 66.9 58.9 61.0 51.6 51.9T_(b) at 23° C. (MPa) 17.9 17.4 19.0 18.5 18.1 15.3 20.9 E_(b) at 23° C.(%) 451 425 429 437 437 386 464 ΔG′ (MPa) 1.95 1.83 1.16 1.23 1.30 1.771.91 tanδ at 50° C., 3% strain 0.122 0.113 0.0877 0.0959 0.0965 0.1180.120

As can be seen in Table 3 and FIG. 2, the 2-PyCN—, PICN—, andPZCN-modified polymers give lower tan δ at 50° C. than the unmodifiedpolymer, indicating that the modification with 2-PyCN, PICN or PZCNreduces hysteresis. The 2-PyCN—, PICN—, and PZCN-modified polymers alsogive lower ΔG′ than the unmodified polymer, indicating that the PayneEffect has been reduced due to the stronger interaction between themodified polymers and carbon black. In contrast, both PhCN— andCH₃CN-modified polymers provide no or very marginal reduction inhysteresis as compared to unmodified polymer.

Example 15 Synthesis of Unmodified cis-1,4-Polybutadiene

2.4 kg of cyclohexane and 300 g of 1,3-butadiene were loaded into a 5-Lnitrogen-purged reactor. As catalyst components, a cyclohexane solutionof NdV (0.09 mmol), a toluene solution of MAO (1.8 mmol), a cyclohexanesolution of DIBAH (4.3 mmol), a toluene solution of DEAC (0.18 mmol),and 1,3-butadiene (4.5 mmol) were combined at 50° C. for 30 min, and theresulting mixture was charged into the reactor. The polymerization wasthen carried out at 80° C. for 60 min. The conversion of 1,3-butadienewas almost 100%.

About 200 g of the resulting polymer cement was removed from the reactorand quenched with a methanol solution containing 1.5 g of2,4-di-t-butyl-p-cresol. The polymer cement was desolventized by steamstripping and drying on a roll that was preheated to 110° C. Theresulting unmodified cis-1,4-polybutadiene had a Mooney viscosity(ML₁₊₄, 100° C.) of 32 and a cis-1,4-linkage content of 95.3%.

Example 16 Synthesis of cis-1,4-Polybutadiene Modified with 2-PyCN and3-Glycidoxypropyltrimethoxysilane (GPMOS)

The remaining polymer cement prepared in Example 15 was kept in thereactor at a temperature of 60° C., and a toluene solution of 2-PyCNprepared (3.0 mmol) was added and reacted for 30 min. Then, a toluenesolution of 3-glycidoxypropyltrimethoxysilane (GPMOS) (0.6 mmol) wasadded and reacted for 30 min. Subsequently, a methanol solutioncontaining 1.5 g of 2,4-di-t-butyl-p-cresol was added to obtain 2.5 kgof a modified polymer cement which was then desolventized by steamstripping and drying on a roll that was preheated to 110° C. Theresulting modified cis-1,4-polybutadiene had a Mooney viscosity (ML₁₊₄,100° C.) of 47 and a cold flow value of 0.6 mg/min.

Polymer cold-flow values were determined as follows for Examples 16-21.Modified cis-1,4-polybutadiene was kept at a temperature of 50° C. andextruded through a 6.35-mm orifice at a pressure of 24.1 kPa. Afterabout 10 minutes of extrusion (i.e., after the extrusion velocity becameconstant), the extruded amount (mg) of the polymer was measured every 30min. for 90 min., and its average value was used as the cold flow value(mg/min).

Example 17 Synthesis of cis-1,4-Polybutadiene Modified with 2-PyCN andDioctyltin Bis(octylmaleate) (DOTBOM)

Modified cis-1,4-polybutadiene was obtained in the same manner as inExamples 15 and 16 except that GPMOS was replaced by dioctyltinbis(octylmaleate) (DOTBOM) (0.15 mmol) was added.

Before modification, the polymer had a Mooney viscosity of 30 and acis-1,4-linkage content of 94.8%. After modification, the polymer had aMooney viscosity of 45 and a cold flow value of 0.8 mg/min.

Example 18 Synthesis of cis-1,4-Polybutadiene Modified with 2-PyCN and3-Isocyanatopropyltriethoxysilane (IPEOS)

Modified cis-1,4-polybutadiene was obtained in the same manner as inExamples 15 and 16 except that GPMOS was replaced by3-isocyanatopropyltriethoxysilane (IPEOS).

Before modification, the polymer had a Mooney viscosity of 33 and acis-1,4-linkage content of 95.1%. After modification, the polymer had aMooney viscosity of 48 and a cold flow value of 0.5 mg/min.

Example 19 Synthesis of Unmodified cis-1,4-Polybutadiene

2.4 kg of cyclohexane and 300 g of 1,3-butadiene were loaded into a 5-Lnitrogen-purged reactor. As catalyst components, a cyclohexane solutionof NdV (0.18 mmol), a toluene solution of MAO (1.8 mmol), a cyclohexanesolution of DIBAH (5.3 mmol), a toluene solution of trimethylsilyliodide (Me₃SiI) (0.36 mmol), and 1,3-butadiene (4.5 mmol) were combinedat 30° C. for 60 min, and the resulting mixture was charged into thereactor. The polymerization was then carried out at 30° C. for 120 min.The conversion of 1,3-butadiene was almost 100%.

About 200 g of the resulting polymer cement was removed from the reactorand quenched with a methanol solution containing 1.5 g of2,4-di-t-butyl-p-cresol. The polymer cement was desolventized by steamstripping and drying on a roll that was preheated to 110° C. Theresulting unmodified cis-1,4-polybutadiene had a Mooney viscosity(ML₁₊₄, 100° C.) of 22 and a cis-1,4-bond content of 99.2%.

Example 20 Synthesis of cis-1,4-Polybutadiene Modified with 2-PyCN andGPMOS

The remaining polymer cement prepared in Example 19 was kept in thereactor at a temperature of 30° C., and a toluene solution of 2-PyCN(6.0 mmol) was added and reacted for 30 min. Then, a toluene solution ofGPMOS (0.6 mmol) was added and reacted for 30 min. Subsequently, amethanol solution containing 1.5 g of 2,4-di-t-butyl-p-cresol was addedto obtain 2.5 kg of a modified polymer cement which was thendesolventized by steam stripping and drying on a roll that was preheatedto 110° C. The resulting modified cis-1,4-polybutadiene had a Mooneyviscosity (ML₁₊₄, 100° C.) of 56 and a cold flow value of 0.4 mg/min.

Example 21 Synthesis of cis-1,4-Polybutadiene Modified with PyCN andSilicon Tetrachloride (STC)

Modified conjugated diene polymer was obtained in the same manner as inExamples 19 and 20 except that GPMOS was replaced with silicontetrachloride (STC).

Before modification, the polymer had a Mooney viscosity of 23 and acis-1,4-linkage content of 99.1%. After modification, the polymer had aMooney viscosity of 63 and a cold flow value of 0.2 mg/min.

Example 22 Synthesis of Unmodified Poly(styrene-co-butadiene)(Unmodified SBR)

To a 5-gallon reactor equipped with turbine agitator blades was added5320 g of hexane, 1320 g of 33.0 wt % styrene in hexane, and 7776 g of22.4 wt % 1,3-butadiene in hexane. To the reactor was charged 11.34 mLof 1.6 M n-butyllithium in hexane and 3.74 mL of 1.6 M2,2-bis(2′-tetrahydrofuryl)propane in hexane. The batch was heated byapplying hot water to the reactor jacket. Once the batch temperaturereached 50° C., the reactor jacket was cooled with cold water. Ninetyminutes after the addition of the catalyst, 402 g of the resultingliving polymer cement was transferred from the reactor into anitrogen-purged bottle, quenched by addition of 3 mL of isopropanolcontaining 0.3 g of 2,6-di-tert-butyl-4-methylphenol, coagulated with 3liters of isopropanol containing 0.5 g of2,6-di-tert-butyl-4-methylphenol, and then drum-dried. The Mooneyviscosity (ML₁₊₄) of the resulting polymer was determined to be 11.5 at100° C. by using a Monsanto Mooney viscometer with a large rotor, aone-minute warm-up time, and a four-minute running time. As determinedby gel permeation chromatography (GPC), the polymer had a number averagemolecular weight (M_(n)) of 120,300 g/mole, a weight average molecularweight (M_(w)) of 125,200 g/mole, and a molecular weight distribution(M_(w)/M_(n)) of 1.04. The ¹H NMR analysis of the polymer indicated thatthe polymer had a styrene content of 19.7 wt % and a 1,2-linkage(butadiene unit) of 57.4%. As measured by differential scanningcalorimetry (DSC), the polymer had a glass transition temperature (Tg)of −32° C. The properties of the resulting unmodified SBR are summarizedin Table 4.

TABLE 4 Physical Properties of Unmodified and Modified SBR Example No.Example 22 Example 23 Example 24 Example 25 Example 26 Polymer typeunmodified unmodified 2-PyCN- 4-PyCN- 2,4-PyDCN- modified modifiedmodified ML₁₊₄ 13.9 49.5 23.1 20.6 48.0 M_(n) 120,300 185,500 135,500138,100 180,400 M_(w) 125,200 194,800 161,200 162,400 238,600M_(w)/M_(n) 1.04 1.05 1.19 1.18 1.32 Cold-flow gauge 2.37 3.11 2.83 2.944.00 (mm at 8 min.) % styrene 19.7 20.0 19.7 19.7 19.7 % 1,2 57.4 55.557.4 57.4 57.4 Tg (° C.) −32 −31 −32 −32 −32

Example 23 Synthesis of Unmodified Poly(styrene-co-butadiene)(Unmodified SBR)

To a 2-gallon reactor equipped with turbine agitator blades was added1597 g of hexane, 399 g of 34.0 wt % styrene in hexane, and 2440 g of22.3 wt % 1,3-butadiene in hexane. To the reactor was charged 2.58 mL of1.6 M n-butyllithium in hexane and 0.85 mL of 1.6 M2,2-bis(2′-tetrahydrofuryl)propane in hexane. The batch was heated byapplying hot water to the reactor jacket. Once the batch temperaturereached 55° C., the reactor jacket was cooled with cold water. Two hoursafter the addition of the catalyst, the polymer cement was removed fromthe reactor and coagulated with 3 gallons of isopropanol containing 7 gof 2,6-di-tert-butyl-4-methylphenol, and then drum-dried. The propertiesof the resulting unmodified SBR are summarized in Table 4.

Example 24 Synthesis of Poly(styrene-co-butadiene) Modified with2-Pyridinecarbonitrile (2-PyCN-Modified SBR)

405 g of the living polymer cement synthesized in Example 22 wastransferred from the reactor to a nitrogen-purged bottle, followed byaddition of 0.88 mL of 0.575 M 2-pyridinecarbonitrile (2-PyCN) intoluene. The bottle was tumbled for 30 minutes in a water bathmaintained at 50° C. The resulting polymer cement was coagulated byadding 3 liters of isopropanol containing 0.5 g of2,6-di-tert-butyl-4-methylphenol and then drum-dried. The properties ofthe resulting 2-PyCN-modified SBR are summarized in Table 4.

Example 25 Synthesis of Poly(styrene-co-butadiene) Rubber Modified with4-Pyridinecarbonitrile (4-PyCN-Modified SBR)

Poly(styrene-co-butadiene) modified with 4-pyridinecarbonitrile (4-PyCN)was prepared by reacting 406 g of the living polymer cement from Example22 with 1.16 mL of 0.435 M 4-PyCN in toluene. The reaction conditionsand polymer work-up procedure were identical to those in Example 24. Theproperties of the resulting 4-PyCN-modified SBR are summarized in Table4.

Example 26 Synthesis of Poly(styrene-co-butadiene) Modified with2,4-Pyridinedicarbonitrile (2,4-PyDCN-Modified SBR)

Poly(styrene-co-butadiene) modified with 2,4-pyridinedicarbonitrile(2,4-PyDCN) was prepared by reacting 401 g of the living polymer cementfrom Example 22 with 1.88 mL of 0.266 M 2,4-PyDCN in toluene. Thereaction conditions and polymer work-up procedure were identical tothose in Example 24. The properties of the resulting 2,4-PyDCN-modifiedSBR are summarized in Table 4.

In FIG. 3, the cold-flow resistance of the unmodified or modified SBRsamples synthesized in Examples 22-26 is plotted against the polymerMooney viscosity. The data indicate that, at the same polymer Mooneyviscosity, the 2-PyCN—, 4-PyCN—, and 2,4-PyDCN-modified polymers showmuch higher residual cold-flow gauge values and accordingly much bettercold-flow resistance than unmodified polymer.

Examples 27-31 Compounding Evaluation of 2-PyCN—, 4-PyCN—, and2,4-PyDCN-Modified SBR against Unmodified SBR

The SBR samples produced in Examples 22-26 were evaluated in a carbonblack filled rubber compound. The compositions of the vulcanizates arepresented in Table 5, wherein the numbers are expressed as parts byweight per hundred parts by weight of rubber (phr).

TABLE 5 Compositions of Rubber Vulcanizates Prepared from SBR IngredientAmount (phr) SBR 100 Carbon black 50 Oil 10 Wax 2 Antioxidant 0.95 Zincoxide 2.5 Stearic acid 2 Accelerators 1.3 Sulfur 1.5 Total 170.25

The Mooney viscosity (ML₁₊₄) of the uncured compound was determined at100° C. by using a Alpha Technologies Mooney viscometer with a largerotor, a one-minute warm-up time, and a four-minute running time. Thetensile mechanical properties of the vulcanizates were measured by usingthe standard procedure described in ASTM-D412. The Payne effect data(ΔG′) and hysteresis data (tan δ) of the vulcanizates were obtained froma dynamic strain sweep experiment, which was conducted at 60° C. and 10Hz with strain sweeping from 0.25% to 15%. ΔG′ is the difference betweenG′ at 0.25% strain and G′ at 14% strain. The physical properties of thevulcanizates are summarized in Table 6 and FIG. 4.

TABLE 6 Physical Properties of Rubber Vulcanizates Prepared from SBRExample No. Example 27 Example 28 Example 29 Example 30 Example 31Polymer used Example 22 Example 23 Example 24 Example 25 Example 26Polymer type unmodified unmodified 2-PyCN- 4-PyCN- 2,4-PyDCN- modifiedmodified modified ML₁₊₄ 40.9 89.1 56.7 53.4 69.0 T_(b) at 23° C. (MPa)19.7 17.6 20.6 21.2 19.8 E_(b) at 23° C. (%) 445 529 405 427 386 ΔG′(MPa) 3.55 1.75 0.76 0.75 0.63 tanδ at 60° C., 5% strain 0.238 0.1570.134 0.139 0.124

As can be seen in Table 6 and FIG. 4, the 2-PyCN—, 4-PyCN, and2,4-PyDCN-modified SBR polymers give lower tan δ at 60° C. than theunmodified SBR, indicating that the modification with 2-PyCN—, 4-PyCN,and 2,4-PyDCN reduces hysteresis. The 2-PyCN—, 4-PyCN, and2,4-PyDCN-modified polymers also gives lower ΔG′ than the unmodifiedSBR, indicating that the Payne Effect has been reduced due to theinteraction between the modified polymers and carbon black.

Various modifications and alterations that do not depart from the scopeand spirit of this invention will become apparent to those skilled inthe art. This invention is not to be duly limited to the illustrativeembodiments set forth herein.

1. A method for preparing a functionalized polymer, the method comprising the steps of: (i) preparing a reactive polymer; and (ii) reacting the reactive polymer with a heterocyclic nitrile compound.
 2. The method of claim 1, where the heterocyclic nitrile compound is defined by the formula θ-C≡N or θ-R—C≡N, where θ is a heterocyclic group and R is a divalent organic group.
 3. The method of claim 2, where θ includes one or more nitrogen atoms.
 4. The method of claim 2, where θ includes one or more oxygen atoms.
 5. The method of claim 2, where θ includes one or more sulfur atoms.
 6. The method of claim 2, where θ includes one or more cyano groups.
 7. The method of claim 2, where the heterocyclic group is aromatic.
 8. The method of claim 2, where the heterocyclic group is non-aromatic.
 9. The method of claim 2, where θ is monocyclic, bicyclic, tricyclic, or multicyclic.
 10. The method of claim 2, where θ is selected from the group consisting of 2-pyridyl, 3-pyridyl, 4-pyridyl, pyrazinyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 3-pyridazinyl, 4-pyridazinyl, N-methyl-2-pyrrolyl, N-methyl-3-pyrrolyl, N-methyl-2-imidazolyl, N-methyl-4-imidazolyl, N-methyl-5-imidazolyl, N-methyl-3-pyrazolyl, N-methyl-4-pyrazolyl, N-methyl-5-pyrazolyl, N-methyl-1,2,3-triazol-4-yl, N-methyl-1,2,3-triazol-5-yl, N-methyl-1,2,4-triazol-3-yl, N-methyl-1,2,4-triazol-5-yl, 1,2,4-triazin-3-yl, 1,2,4-triazin-5-yl, 1,2,4-triazin-6-yl, 1,3,5-triazinyl, N-methyl-2-pyrrolin-2-yl, N-methyl-2-pyrrolin-3-yl, N-methyl-2-pyrrolin-4-yl, N-methyl-2-pyrrolin-5-yl, N-methyl-3-pyrrolin-2-yl, N-methyl-3-pyrrolin-3-yl, N-methyl-2-imidazolin-2-yl, N-methyl-2-imidazolin-4-yl, N-methyl-2-imidazolin-5-yl, N-methyl-2-pyrazolin-3-yl, N-methyl-2-pyrazolin-4-yl, N-methyl-2-pyrazolin-5-yl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, N-methylindol-2-yl, N-methylindol-3-yl, N-methylisoindol-1-yl, N-methylisoindol-3-yl, 1-indolizinyl, 2-indolizinyl, 3-indolizinyl, 1-phthalazinyl, 2-quinazolinyl, 4-quinazolinyl, 2-quinoxalinyl, 3-cinnolinyl, 4-cinnolinyl, 1-methylindazol-3-yl, 1,5-naphthyridin-2-yl, 1,5-naphthyridin-3-yl, 1,5-naphthyridin-4-yl, 1,8-naphthyridin-2-yl, 1,8-naphthyridin-3-yl, 1,8-naphthyridin-4-yl, 2-pteridinyl, 4-pteridinyl, 6-pteridinyl, 7-pteridinyl, 1-methylbenzimidazol-2-yl, 6-phenanthridinyl, N-methyl-2-purinyl, N-methyl-6-purinyl, N-methyl-8-purinyl, N-methyl-β-carbolin-1-yl, N-methyl-β-carbolin-3-yl, N-methyl-β-carbolin-4-yl, 9-acridinyl, 1,7-phenanthrolin-2-yl, 1,7-phenanthrolin-3-yl, 1,7-phenanthrolin-4-yl, 1,10-phenanthrolin-2-yl, 1,10-phenanthrolin-3-yl, 1,10-phenanthrolin-4-yl, 4,7-phenanthrolin-1-yl, 4,7-phenanthrolin-2-yl, 4,7-phenanthrolin-3-yl, 1-phenazinyl, 2-phenazinyl, pyrrolidino, piperidino, 2-furyl, 3-furyl, 2-benzo[b]furyl, 3-benzo[b]furyl, 1-isobenzo[b]furyl, and 3-isobenzo[b]furyl, 2-naphtho[2,3-b]furyl, 3-naphtho[2,3-b]furyl, 2-thienyl, 3-thienyl, 2-benzo[b]thienyl, 3-benzo[b]thienyl, 1-isobenzo[b]thienyl, 3-isobenzo[b]thienyl, 2-naphtho[2,3-b]thienyl, 3 -naphtho[2,3-b]thienyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-thiazolyl, 4-thiazolyl, 5-thiazolyl, 3-isothiazolyl, 4-isothiazolyl, 5-isothiazolyl, 1,2,3-oxadiazol-4-yl, 1,2,3-oxadiazol-5-yl, 1,3,4-oxadiazol-2-yl, 1,2,3-thiadiazol-4-yl, 1,2,3-thiadiazol-5-yl, 1,3,4-thiadiazol-2-yl, 2-oxazolin-2-yl, 2-oxazolin-4-yl, 2-oxazolin-5-yl 3-isoxazolinyl, 4-isoxazolinyl, 5-isoxazolinyl, 2-thiazolin-2-yl, 2-thiazolin-4-yl, 2-thiazolin-5-yl, 3-isothiazolinyl, 4-isothiazolinyl, 5-isothiazolinyl, 2-benzothiazolyl, and morpholino groups.
 12. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2-pyridinecarbonitrile, 3-pyridinecarbonitrile, 4-pyridinecarbonitrile, pyrazinecarbonitrile, 2-pyrimidinecarbonitrile, 4-pyrimidinecarbonitrile, 5-pyrimidinecarbonitrile, 3-pyridazinecarbonitrile, 4-pyridazinecarbonitrile, N-methyl-2-pyrrolecarbonitrile, N-methyl-3-pyrrolecarbonitrile, N-methyl-2-imidazolecarbonitrile, N-methyl-4-imidazolecarbonitrile, N-methyl-5-imidazolecarbonitrile, N-methyl-3-pyrazolecarbonitrile, N-methyl-4-pyrazolecarbonitrile, N-methyl-5-pyrazolecarbonitrile, N-methyl-1,2,3-triazole-4-carbonitrile, N-methyl-1,2,3-triazole-5-carbonitrile, N-methyl-1,2,4-triazole-3-carbonitrile, N-methyl-1,2,4-triazole-5-carbonitrile, 1,2,4-triazine-3-carbonitrile, 1,2,4-triazine-5-carbonitrile, 1,2,4-triazine-6-carbonitrile, 1,3,5-triazinecarbonitrile, N-methyl-2-pyrroline-2-carbonitrile, N-methyl-2-pyrroline-3-carbonitrile, N-methyl-2-pyrroline-4-carbonitrile, N-methyl-2-pyrroline-5-carbonitrile, N-methyl-3-pyrroline-2-carbonitrile, N-methyl-3-pyrroline-3-carbonitrile, N-methyl-2-imidazoline-2-carbonitrile, N-methyl-2-imidazoline-4-carbonitrile, N-methyl-2-imidazoline-5-carbonitrile, N-methyl-2-pyrazoline-3-carbonitrile, N-methyl-2-pyrazoline-4-carbonitrile, N-methyl-2-pyrazoline-5-carbonitrile, 2-quinolinecarbonitrile, 3-quinolinecarbonitrile, 4-quinolinecarbonitrile, 1 -isoquinolinecarbonitrile, 3-isoquinolinecarbonitrile, 4-isoquinolinecarbonitrile, N-methylindole-2-carbonitrile, N-methylindole-3-carbonitrile, N-methylisoindole-1-carbonitrile, N-methylisoindole-3-carbonitrile, 1-indolizinecarbonitrile, 2-indolizinecarbonitrile, 3-indolizinecarbonitrile, 1-phthalazinecarbonitrile, 2-quinazolinecarbonitrile, 4-quinazolinecarbonitrile, 2-quinoxalinecarbonitrile, 3-cinnolinecarbonitrile, 4-cinnolinecarbonitrile, 1-methylindazole-3-carbonitrile, 1,5-naphthyridine-2-carbonitrile, 1,5-naphthyridine-3-carbonitrile, 1,5-naphthyridine-4-carbonitrile, 1,8-naphthyridine-2-carbonitrile, 1,8-naphthyridine-3-carbonitrile, 1,8-naphthyridine-4-carbonitrile, 2-pteridinecarbonitrile, 4-pteridinecarbonitrile, 6-pteridinecarbonitrile, 7-pteridinecarbonitrile, 1-methylbenzimidazole-2-carbonitrile, phenanthridine-6-carbonitrile, N-methyl-2-purinecarbonitrile, N-methyl-6-purinecarbonitrile, N-methyl-8-purinecarbonitrile, N-methyl-β-carboline-1-carbonitrile, N-methyl-P-carboline-3-carbonitrile, N-methyl-β-carboline-4-carbonitrile, 9-acridinecarbonitrile, 1,7-phenanthroline-2-carbonitrile, 1,7-phenanthroline-3-carbonitrile, 1,7-phenanthroline-4-carbonitrile, 1,10-phenanthroline-2-carbonitrile, 1,10-phenanthroline-3-carbonitrile, 1,10-phenanthroline-4-carbonitrile, 4,7-phenanthroline-1-carbonitrile, 4,7-phenanthroline-2-carbonitrile, 4,7-phenanthroline-3-carbonitrile, 1-phenazinecarbonitrile, 2-phenazinecarbonitrile, 1-pyrrolidinecarbonitrile, and 1-piperidinecarbonitrile.
 13. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2-furonitrile, 3-furonitrile 2-benzo[b]furancarbonitrile, 3-benzo[b]furancarbonitrile, isobenzo[b]furan-1-carbonitrile, isobenzo[b]furan-3-carbonitrile, naphtho[2,3-b]furan-2-carbonitrile, and naphtho[2,3-b]furan-3-carbonitrile.
 14. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2-thiophenecarbonitrile, 3-thiophenecarbonitrile, benzo[b]thiophene-2-carbonitrile, benzo[b]thiophene-3-carbonitrile, isobenzo[b]thiophene-1-carbonitrile, isobenzo[b]thiophene-3-carbonitrile, naphtho[2,3-b]thiophene-2-carbonitrile, and naphtho[2,3-b]thiophene-3-carbonitrile.
 15. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2-oxazolecarbonitrile, 4-oxazolecarbonitrile, 5-oxazolecarbonitrile, 3-isoxazolecarbonitrile, 4-isoxazolecarbonitrile, 5-isoxazolecarbonitrile, 2-thiazolecarbonitrile, 4-thiazolecarbonitrile, 5-thiazolecarbonitrile, 3-isothiazolecarbonitrile, 4-isothiazolecarbonitrile, 5-isothiazolecarbonitrile, 1,2,3-oxadiazole-4-carbonitrile, 1,2,3-oxadiazole-5-carbonitrile, 1,3,4-oxadiazole-2-carbonitrile, 1,2,3-thiadiazole-4-carbonitrile, 1,2,3-thiadiazole-5-carbonitrile, 1,3,4-thiadiazole-2-carbonitrile, 2-oxazoline-2-carbonitrile, 2-oxazoline-4-carbonitrile, 2-oxazoline-5-carbonitrile, 3-isoxazolinecarbonitrile, 4-isoxazolinecarbonitrile, 5-isoxazolinecarbonitrile, 2-thiazoline-2-carbonitrile, 2-thiazoline-4-carbonitrile, 2-thiazoline-5-carbonitrile, 3-isothiazolinecarbonitrile, 4-isothiazolinecarbonitrile, 5-isothiazolinecarbonitrile, benzothiazole-2-carbonitrile, and 4-morpholinecarbonitrile.
 16. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2,3-pyridinedicarbonitrile, 2,4-pyridinedicarbonitrile, 2,5-pyridinedicarbonitrile, 2,6-pyridinedicarbonitrile, 3,4-pyridinedicarbonitrile, 2,4-pyrimidinedicarbonitrile, 2,5-pyrimidinedicarbonitrile, 4,5-pyrimidinedicarbonitrile, 4,6-pyrimidinedicarbonitrile, 2,3-pyrazinedicarbonitrile, 2,5-pyrazinedicarbonitrile, 2,6-pyrazinedicarbonitrile, 2,3-furandicarbonitrile, 2,4-furandicarbonitrile, 2,5-furandicarbonitrile, 2,3-thiophenedicarbonitrile, 2,4-thiophenedicarbonitrile, 2,5-thiophenedicarbonitrile, N-methyl-2,3-pyrroledicarbonitrile, N-methyl-2,4-pyrroledicarbonitrile, N-methyl-2,5-pyrroledicarbonitrile, 1,3,5-triazine-2,4-dicarbonitrile, 1,2,4-triazine-3,5-dicarbonitrile, 1,2,4-triazine-3,6-dicarbonitrile, 2,3,4-pyridinetricarbonitrile, 2,3,5-pyridinetricarbonitrile, 2,3,6-pyridinetricarbonitrile, 2,4,5-pyridinetricarbonitrile, 2,4,6-pyridinetricarbonitrile, 3,4,5-pyridinetricarbonitrile, 2,4,5-pyrimidinetricarbonitrile, 2,4,6-pyrimidinetricarbonitrile, 4,5,6-pyrimidinetricarbonitrile, pyrazinetricarbonitrile, 2,3,4-furantricarbonitrile, 2,3,5-furantricarbonitrile, 2,3,4-thiophenetricarbonitrile, 2,3,5-thiophenetricarbonitrile, N-methyl-2,3,4-pyrroletricarbonitrile, N-methyl-2,3,5-pyrroletricarbonitrile, 1,3,5-triazine-2,4,6-tricarbonitrile, and 1,2,4-triazine-3,5,6-tricarbonitrile.
 17. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2-pyridylacetonitrile, 3-pyridylacetonitrile, 4-pyridylacetonitrile, pyrazinylacetonitrile, 2-pyrimidinylacetonitrile, 4-pyrimidinylacetonitrile, 5-pyrimidinylacetonitrile, 3-pyridazinylacetonitrile, 4-pyridazinylacetonitrile, N-methyl-2-pyrrolylacetonitrile, N-methyl-3-pyrrolylacetonitrile, N-methyl-2-imidazolylacetonitrile, N-methyl-4-imidazolylacetonitrile, N-methyl-5-imidazolylacetonitrile, N-methyl-3-pyrazolylacetonitrile, N-methyl-4-pyrazolylacetonitrile, N-methyl-5-pyrazolylacetonitrile, 1,3,5-triazinylacetonitrile, 2-quinolylacetonitrile, 3-quinolylacetonitrile, 4-quinolylacetonitrile, 1-isoquinolylacetonitrile, 3-isoquinolylacetonitrile, 4-isoquinolylacetonitrile, 1-indolizinylacetonitrile, 2-indolizinylacetonitrile, 3-indolizinylacetonitrile, 1 -phthalazinylacetonitrile, 2-quinazolinylacetonitrile, 4-quinazolinylacetonitrile, 2-quinoxalinylacetonitrile, 3-cinnolinylacetonitrile, 4-cinnolinylacetonitrile, 2-pteridinylacetonitrile, 4-pteridinylacetonitrile, 6-pteridinylacetonitrile, 7-pteridinylacetonitrile, 6-phenanthridinylacetonitrile, N-methyl-2-purinylacetonitrile, N-methyl-6-purinylacetonitrile, N-methyl-8-purinylacetonitrile, 9-acridinylacetonitrile, 1,7-phenanthrolin-2-ylacetonitrile, 1,7-phenanthrolin-3-ylacetonitrile, 1,7-phenanthrolin-4-ylacetonitrile, 1,10-phenanthrolin-2-ylacetonitrile, 1,10-phenanthrolin-3-ylacetonitrile, 1,10-phenanthrolin-4-ylacetonitrile, 4,7-phenanthrolin-1-ylacetonitrile, 4,7-phenanthrolin-2-ylacetonitrile, 4,7-phenanthrolin-3-ylacetonitrile, 1-phenazinylacetonitrile, 2-phenazinylacetonitrile, pyrrolidinoacetonitrile, and piperidinoacetonitrile.
 18. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2-furylacetonitrile, 3-furylacetonitrile, 2-benzo[b]furylacetonitrile, 3-benzo[b]furylacetonitrile, 1-isobenzo[b]furylacetonitrile, 3-isobenzo[b]furylacetonitrile, 2-naphtho[2,3-b]furylacetonitrile, and 3-naphtho[2,3-b]furylacetonitrile.
 19. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2-thienylacetonitrile, 3-thienylacetonitrile, 2-benzo[b]thienylacetonitrile, 3-benzo[b]thienylacetonitrile, 1-isobenzo[b]thienylacetonitrile, 3-isobenzo[b]thienylacetonitrile, 2-naphtho[2,3-b]thienylacetonitrile, and 3-naphtho[2,3-b]thienylacetonitrile.
 20. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2-oxazolylacetonitrile, 4-oxazolylacetonitrile, 5-oxazolylacetonitrile, 3-isoxazolylacetonitrile, 4-isoxazolylacetonitrile, 5-isoxazolylacetonitrile, 2-thiazolylacetonitrile, 4-thiazolylacetonitrile, 5-thiazolylacetonitrile, 3-isothiazolylacetonitrile, 4-isothiazolylacetonitrile, 5-isothiazolylacetonitrile, 3-isoxazolinylacetonitrile, 4-isoxazolinylacetonitrile, 5-isoxazolinylacetonitrile, 3-isothiazolinylacetonitrile, 4-isothiazolinylacetonitrile, 5-isothiazolinylacetonitrile, 2-benzothiazolylacetonitrile, and morpholinoacetonitrile.
 21. The method of claim 1, where the heterocyclic nitrile compound is selected from the group consisting of 2,3-pyridinediacetonitrile, 2,4-pyridinediacetonitrile, 2,5-pyridinediacetonitrile, 2,6-pyridinediacetonitrile, 3,4-pyridinediacetonitrile, 2,4-pyrimidinediacetonitrile, 2,5-pyrimidinediacetonitrile, 4,5-pyrimidinediacetonitrile, 4,6-pyrimidinediacetonitrile, 2,3-pyrazinediacetonitrile, 2,5-pyrazinediacetonitrile, 2,6-pyrazinediacetonitrile, 2,3-furandiacetonitrile, 2,4-furandiacetonitrile, 2,5-furandiacetonitrile, 2,3-thiophenediacetonitrile, 2,4-thiophenediacetonitrile, 2,5-thiophenediacetonitrile, N-methyl-2,3-pyrrolediacetonitrile, N-methyl-2,4-pyrrolediacetonitrile, N-methyl-2,5-pyrrolediacetonitrile, 1,3,5-triazine-2,4-diacetonitrile, 1,2,4-triazine-3,5-diacetonitrile, 1,2,4-triazine-3,6-diacetonitrile, 2,3,4-pyridinetriacetonitrile, 2,3,5-pyridinetriacetonitrile, 2,3,6-pyridinetriacetonitrile, 2,4,5-pyridinetriacetonitrile, 2,4,6-pyridinetriacetonitrile, 3,4,5-pyridinetriacetonitrile, 2,4,5-pyrimidinetriacetonitrile, 2,4,6-pyrimidinetriacetonitrile, 4,5,6-pyrimidinetriacetonitrile, pyrazinetriacetonitrile, 2,3,4-furantriacetonitrile, 2,3,5-furantriacetonitrile, 2,3,4-thiophenetriacetonitrile, 2,3,5-thiophenetriacetonitrile, N-methyl-2,3,4-pyrroletriacetonitrile, N-methyl-2,3,5-pyrroletriacetonitrile, 1,3,5-triazine-2,4,6-triacetonitrile, and 1,2,4-triazine-3,5,6-triacetonitrile.
 22. The method of claim 1, where the heterocyclic nitrile compound is 2-pyridinecarbonitrile.
 23. The method of claim 1, where the heterocyclic nitrile compound is 2-pyrimidinecarbonitrile.
 24. The method of claim 1, where the heterocyclic nitrile compound is pyrazinecarbonitrile.
 25. The method of claim 1, where the heterocyclic nitrile compound is 2-pyridylacetonitrile.
 26. The method of claim 1, where the heterocyclic nitrile compound is 3-pyridylacetonitrile.
 27. The method of claim 1, where the heterocyclic nitrile compound is 4-pyridylacetonitrile.
 28. The method of claim 1, where said step of reacting the reactive polymer with a heterocyclic nitrile compound occurs before the reactive polymer is quenched.
 29. The method of claim 1, where said step of preparing a reactive polymer includes polymerizing conjugated diene monomer and optionally monomer copolymerizable therewith.
 30. The method of claim 1, where said step of preparing a reactive polymer includes employing a coordination catalyst system.
 31. The method of claim 30, where said coordination catalyst system includes a lanthanide-based catalyst system.
 32. The method of claim 31, where the lanthanide-based catalyst system includes (a) a lanthanide compound, (b) an alkylating agent, and (c) a halogen-containing compound.
 33. The method of claim 32, where the alkylating agent includes an aluminoxane and an organoaluminum compound represented by the formula AlR_(n)X_(3-n), where each R, which may be the same or different, is a mono-valent organic group that is attached to the aluminum atom via a carbon atom, where each X, which may be the same or different, is a hydrogen atom, a halogen atom, a carboxylate group, an alkoxide group, or an aryloxide group, and where n is an integer of 1 to
 3. 34. The method of claim 1, where said step of preparing a reactive polymer takes place within a polymerization mixture including less than 20% by weight of orgainic solvent.
 35. The method of claim 32, where the molar ratio of the heterocyclic nitrile compound to the lanthanide metal of the lanthanide-based catalyst is from about 1:1 to about 200:1.
 36. The method of claim 1, where said step of preparing a reactive polymer includes employing an anionic initiator.
 37. The method of claim 36, where said anionic initiator includes an organolithium compound.
 38. The method of claim 37, where said organolithium compound is selected from the group consisting of an alkyllithium compound, an aryllithium compound, a heterocyclic lithium compound, and a trialkyltinlithium compound.
 39. A method for preparing a functional polymer, the method comprising the steps of: (i) introducing conjugated diene monomer, optionally monomer copolymerizable therewith, and a catalyst or initiator to form a polymerization mixture; and (ii) adding a heterocyclic nitrile compound to the polymerization mixture.
 40. A method for preparing a polymer, the method comprising: (i) preparing an active polymerization mixture; and (ii) adding a heterocyclic nitrile compound to the active polymerization mixture.
 41. The method of claim 40, where said step of preparing an active polymerization mixture includes introducing conjugated diene monomer and a lanthanide-based catalyst system.
 42. The method of claim 40, where said step of preparing an active polymerization mixture includes introducing a monomer and an anionic polymerization initiator.
 43. A functionalized polymer prepared by the steps of: (i) polymerizing monomer to form a reactive polymer; and (ii) reacting the reactive polymer with a heterocyclic nitrile compound.
 44. The functionalized polymer of claim 43, where the monomer includes conjugated diene monomer, and the reactive polymer prepared therefrom is a reactive cis-1,4-polydiene.
 45. The functionalized polymer of claim 44, where the conjugated diene monomer is 1,3-butadiene, and the reactive polymer prepared therefrom is a reative cis-1,4-polybutadiene.
 46. A tire prepared from a rubber composition including the functionalized polymer of claim
 43. 47. A functionalized polymer defined by at least one of the formulae:

where π is a polymer chain, θ is a heterocyclic group, and R is a divalent organic group.
 48. A method for preparing a polymer, the method comprising: (i) preparing an active polymerization mixture; (ii) adding a heterocyclic nitrile compound to the active polymerization mixture; and (iii) adding a co-functionalizing agent to the active polymerization mixture.
 49. The method of claim 48, where the co-functionalizing agent is added to the active polymerization mixture after the step of adding the heterocyclic nitrile compound.
 50. The method of claim 48, where the co-functionalizing agent is added to the active polymerization mixture before the step of adding the heterocyclic nitrile compound.
 51. The method of claim 48, where the co-functionalizing agent is added to the active polymerization mixture together with the heterocyclic nitrile compound.
 52. The method of claim 49, where the co-functionalizing agent is added to the active polymerization mixture at least 5 minutes after the step of adding the heterocyclic nitrile compound.
 53. The method of claim 48, where the co-functionalizing agent is selected from the group consisting of metal halides, metalloid halides, alkoxysilanes, hydrocarbylmetal carboxylates, hydrocarbylmetal ester-carboxylates, and alkoxystannanes.
 54. The method of claim 48, where the co-functionalizing agent is selected from the group consisting of compounds represented by the formulae (1) R¹ _(n)M¹X_(4-n), (2) M¹X₄, and (3) M²X₃, where each R¹ in the formula (1) is individually a mono-valent organic group containing 1 to about 20 carbon atoms, M¹ in the formulae (1) and (2) represents a tin atom, silicon atom, or germanium atom, M² in the formula (3) represents a phosphorous atom, X in the formulae (1)-(3) represents a halogen atom, and n in the formula (1) represents an integer of from 0 to about
 3. 55. The method of claim 48, where the co-functionalizing agent is an alkoxysilane including at least one group selected from the group consisting of an epoxy group and an isocyanate group.
 56. The method of claim 48, where the co-functionalizing agent is a compound represented by the formula (4) R² _(m)M³(OC(O)R²)_(4-m), where each R² is individually a mono-valent organic group containing 1 to about 20 carbon atoms, M³ represents a tin atom, silicon atom or germanium atom, and m represents an integer of 0-2.
 57. The method of claim 48, where the co-functionalizing agent is a compound represented by the formula (5) R² _(m)M³(OCO—R³—CO(O)R²)_(4-m) where each R² is individually a mono-valent organic group containing 1 to about 20 carbon atoms, R³ is a divalent organic group, M³ represents a tin atom, silicon atom or germanium atom, and m represents an integer of from 0 to
 2. 